NEW YORK — Anna Sui’s romp of a collection featured a double whammy: models on the runway and an amusing film behind them, done by Zoe Cassavetes, of bright young things at a faux party — also in the clothes. There were faux Mod looks, Twiggy looks and plenty of schoolgirl styles as Sui rifled through the Sixties once again. Here, the little trompe l’oeil dress. For more, see pages 4 and 5.