Lots of designers are talking escapism this week, but for Marchesa, dreamy flights of fancy are actually their stock-in-trade. And it was business as usual at the Chelsea Art Museum, where a dense crowd that included Natalia Vodianova, Diane Kruger, and Helena Christensen flowed, oohing and aahing, around tulle-swathed models perched on white cubes. “I wanted the whole thing to be like a fairy tale,” explained Marchesa’s designer, Georgina Chapman