Ms. Rubenstein, 33, was at a party celebrating her recent leap from teen magazines—she founded the upstart CosmoGirl! in 1998 at age 26 and took over the venerable Seventeen in 2003—into the heavily saturated world of television reality competitions. That night, a series called Miss Seventeen would premiere on MTV: a sort of adolescent America’s Next Top Model, with Ms. Rubenstein in the Tyra Banks–Donald Trump role of judging teenage girls competing for a Seventeen cover and a college scholarship. A trailer showed 17 nymphs comically squealing and brawling in a Manhattan loft apartment. “I hate girls who dress like sluts,” declared one. “You’re the fakest person here!” screamed another.

The fact that young people will often resort to Machiavellian or downright appalling behavior when placed in a house full of video cameras is a truth understood by many American television-network executives. That Ms. Rubenstein appreciates this as well, and is willing to exploit it, demonstrates a certain craving to raise her own profile—that of a kooky, demanding, unpredictable media figure—as she tinkers with the once-dominant Seventeen brand, which has struggled in recent years. “I think extending the brand with the TV show is a great idea,” said Bonnie Fuller, Ms. Rubenstein’s former boss at Hearst’s Cosmopolitan, now the editorial director of American Media. “Your readers become very involved with you. If a magazine is really working, it’s because it has become a part of readers’ lives, so why wouldn’t they want to see it come to life more on television?”

Earlier that day, in her sherbet-colored office on Broadway at 40th Street, Ms. Rubenstein explained that the idea for the show came to her during one of Seventeen’s routine cover-model contests, when she went to meet five finalists who’d just been flown to New York. “Just as I was walking over there, the girl who’s the winner gave me the dirtiest look,” the editor said, lounging on a pink armchair in a black suit and cartoonish patent-leather high heels. “And she didn’t know who I was, because her mother had submitted her. But I remember thinking, ‘You know, you have done everything on paper that one should do in order to be considered a role model, but yet you’re a total B-I-T-C-H.’ And there’s no way that our system, being as two-dimensional as it is, could really capture that. And so I started fantasizing: What if we had a reality show, and what if we could be watching them all the time … ?”

From Sassy to Seventeen

Ms. Rubenstein speaks in a childish drawl, with sentences that spike up in pitch toward the end, and has retained the slightly awkward body language of the gangly teenager she once was: growing up Iranian-American on Long Island, lonely and awkward, “an outsider,” which led to an almost religious obsession with teenage magazines. “I wish I could reach back to that girl, because that girl was sad,” she said. “That’s what gives me my purpose.” At age 19, she visited a psychic, who predicted that young Atoosa would have a big media career. “I do feel like it’s my destiny,” Ms. Rubenstein said.

She interned at Jane Pratt’s late, lamented Sassy while attending Barnard and joined Cosmopolitan right out of college, becoming a senior fashion editor there. In 1998, Hearst Magazines president Cathie Black tapped her to start CosmoGirl!, which was designed to sell fashion, beauty and boyfriend advice to future Cosmopolitan readers. It was a huge success, and competing spin-offs like TeenVogue and ElleGirl soon followed (Teen People came first), all carving into the coveted adolescent market previously reigned by Seventeen alone. By the time Hearst itself acquired Seventeen in 2003, the magazine was badly ailing: its graphics and photography muted and muddy, its glory days of Brooke Shields layouts and fat, peppy back-to-school issues but a distant memory.

“With CosmoGirl!, I built my dream house, you know?” said Ms. Rubenstein, who has been married to Ari Rubenstein, a full-time securities trader, for seven years and lives with him in Trump Place on the Upper West Side (they also own a house in East Hampton). “With Seventeen, it was a totally different project, in that I inherited this magnificent estate, in the best location possible; however, it was in complete disarray. It was trashed. I mean, before we could even redecorate or renovate, we had to clean, you know?”

Indeed, after she arrived at Seventeen, there was a period of intense turmoil when a large portion of the masthead left or was let go and replaced by her own team. “I feel like I stopped it with my chest,” said Ms. Rubenstein of the downward momentum at the magazine. It was, she added, “the hardest year of my professional life.” During her first two years, many staff editors she’d hired came and went; two deputy editors arrived and quit after several months each (although Ms. Rubenstein ended up hiring back her predecessor, Sabrina Weill, as Seventeen’s Special Projects Director). “The magazine is really a cause for her,” said a former employee. “If you are not completely committed and enveloped in the same cause, it’s very difficult to survive.”

Shortly after Ms. Rubenstein took the gig at Seventeen, someone leaked an e-mail from her zealous assistant, Charlene Fabbiano, outlining complex procedures for interacting with the boss (“Whenever someone has an appointment with Atoosa, they should see me FIRST—never go directly into her office,” read one choice tidbit), to Women’s Wear Daily, which led to an ongoing online string of sniping about the young editrix. “I mean, sometimes when people write mean stuff, it hurts me, because my family reads it, you know?” Ms. Rubenstein said. “And I feel like sometimes … I don’t know if you call them media writers—sometimes it’s bloggers or whatever—I think they lose the humanity of it. I think about it when they write about other people, too: That’s someone’s mother, that’s someone’s daughter. That’s someone who worked really hard to get to where they are. Why would you say something about what they’re wearing in such a mean way?”

She doesn’t usually read blogs, although sometimes “people will send” items to her, “just as an F.Y.I.,” she said. “I don’t care so much any more. I remember there were a couple of things that were truly—it wasn’t just about me being mean. It was just false, incorrect information. I remember at that point thinking, ‘You know what? It’s just fish wrap.’”

Cathie Black’s Pajama Party

And yet Ms. Rubenstein is clearly savvy enough to understand that an ethos of bitchiness could potentially translate into big ratings and increased visibility for her brand, and herself.

Miss Seventeen features “A students” from around the country crammed into a loft apartment in Tribeca, decorated in MTV’s signature Real World style. In the first show, Jill from Morton, Ill., announced: “I’m not here to make friends. I’m here for the competition.” Adds Brianne, from Polson, Mon.: “Atoosa is, like, who I wanna be.” One young lovely, Caroline, said she was “especially concerned with the way that young girls are portrayed in the media.” It is all accompanied by lots of squealing and shrieking and tears.

“Oh, there was a lot of fighting. A lot of fighting,” said Ms. Rubenstein, who maintains a stern, icy presence on the show, in contrast with her exuberant, friendly real-life persona. “You know, there were moments when they would just turn on one girl in the house, and you’re sitting there watching it happen. And it’s sooo uncomfortable. There were a couple of cases where legal had to get involved, you know?”

When asked what kind of message Miss Seventeen might be sending to America’s youth, Ms. Rubenstein said: “While the bad girls and the bad behavior may be the star of the show, it’s only the good girls that advance and get rewarded. So that’s the lesson, you know? Bad behavior does not go unpunished.”

Hearst Magazines president Cathie Black dialed in from the Magazine Publishers Association convention in Puerto Rico and said she was contemplating having a pajama party to watch the premiere of Miss Seventeen that night in her hotel. “I think the message is a really smart one, which is: It’s who you are inside as much as who you are on the outside,” Ms. Black said. “That’s what this whole process of selection is about. It’s not just about when you’re in front of the camera, but what do you do when the door closes or the movie camera is off? What are the dynamics as they try to find a girl who is incredibly talented and smart and ambitious and able, but who is also a really good girl.”

Ms. Rubenstein wanted to make clear that Miss Seventeen is not all fun and froth, that increasing the awareness of social causes among her readers is a major priority of hers. “My process, no matter what I work on, has the same end result and vision,” she said. “And that end result and vision is to bring truth to young women in their lives.”

But despite all this lofty talk, she seems to have not yet fully extracted herself from the Mean Girls drama of female adolescence. “CosmoGirl! was a very personal and special project, because I was making a magazine for the girl that I was,” Ms. Rubenstein said. “She didn’t fit in. Seventeen is a different girl. Seventeen is the girl that made fun of that girl, you know, in a way. Because she’s the girl at school who has more confidence; she’s the girl who does fit in.”

It remains to be seen, of course, whether Ms. Rubenstein can get the popular gals in high school reading Seventeen again. In the period of January to September 2005, ad pages are up a slim 0.5 percent from the same period in 2004, as opposed to 32.7 percent for ElleGirl and 29.8 percent for TeenVogue, according Magazine Publishers of America data. Ms. Rubenstein countered that newsstand sales of her revamped magazine were up 17 percent in the last half of 2004 (and up about 5 percent in the first half of 2005, Ms. Black added). The editor said that the office culture had settled down considerably at Seventeen and compared her management style to being “a conductor of an orchestra,” with her employees as “the most magnificent, talented musicians.” Don’t expect any Devil Wears Ann Taylor romans à clef anytime soon. Ms. Fabbiano, her assistant, has been with Ms. Rubenstein for five years, and told The Observer that Ms. Rubenstein “was the best boss she’d ever worked for.”

Between the television schedule and putting out a magazine, Ms. Rubenstein said she hasn’t had much time to contemplate her next move or even consider additional projects. “I don’t have children,” she said. “Most of the girls that I’m friends with who got married when I did have a couple of kids. But I feel like my readers are my kids.” When asked whether she would consider writing a book, she said, “I should, shouldn’t I? I should. I don’t have time. You know? Some people—agents—call me all the time, and publishers call me. They say, ‘I can get you a ghost writer, don’t worry, it’d be so easy.’ But I would never do that.”

Ms. Rubenstein said that if she ever did pursue a book project, it would have to be something “to help girls.” Helping girls is her mission in life, she said, jumping up to answer her cell phone.