Ever since he decamped to Los Angeles almost one year ago, it’s rare that Donald Robertson makes a return to Manhattan. Although when he does, he’s welcomed with much celebration. Last night, the cult-favorite artist and cosmetic exec and his boss, Estée Lauder’s Executive Group President John Dempsey took to the stage at The Box on the Lower East Side to debut a new collaboration between the new online beauty brand, Flirt Cosmetics, and pop culture enigma, Amber Rose, slated to debut on September 15th.