Renoir, Impressionism, and Full-Length Painting made for a fitting backdrop at last night’s Belle Epoque Ball, hosted by the Young Fellows of the Frick Collection. Photographers dashed from gallery to gallery setting up portraits of the fête’s upwardly mobile twenty- and thirtysomethings in front of grand-scale paintings of upwardly mobile Parisians circa the 1880′s. With a fin de siècle dress code, there were as many bustles in the crowd as there were on the walls. Instead of Renoir’s ubiquitous parasols, the party girls clutched cell phones and snapped pictures of themselves when the guards weren’t looking. Donna Karan sponsored the event, and she was well represented by the evening’s chairmen Olivia Chantecaille, Lydia Fenet, Claiborne Swanson Frank, Clare McKeon, Sloan Overstrom, and Joann Pailey (pictured, above). Rule breakers in the crowd wore short Proenza Schouler and Prabal Gurung. I was part of the Oscar de la Renta contingent, in a pre-fall dress modeled after John Singer Sargent’s famous Madame X. Bill Cunningham took particular notice of OscarPRGirl Erika Bearman’s (pictured, below) yellow poppy gown from Spring. Which was fitting: Oscar and Annette de la Renta, along with SJP and others, are chairing the Carnegie Hall Medal of Excellence gala honoring the legendary photographer next month.