I think the ballet world and the fashion world have a little mutual infatuation thing going on.
Haute couture designers just love to make costumes for ballets. From Valentino to Christian Lacroix to Stella McCartney—the kings and queens of the runway just can't stay away from ballet's best and brightest. But the equation goes the other way, too: Ballet dancers tend to have an amazing sense of personal style, putting together all kinds of creative looks. (It probably doesn't hurt that many of them look like runway models!)