When Elsa met Miuccia — it’s the premise behind this year’s exhibit from the Costume Institute at the  Metropolitan Museum. For Schiaparelli and Prada: Impossible Conversations, director Baz Luhrmann (of Moulin Rouge fame) created videos of simulated conversations between the two great designers, drawing a straight line between their ideas and designs, from their unconventional ideas of beauty to their love of exotic materials and surreal details. Tonight, the fashion flock is lining up the red carpet — the Vogue editors in Schiaparelli’s signature pink — in celebration at the annual Met Gala.