Florence Welch, front woman of Florence and the Machine, is facing the U.S. leg of her tour in a few weeks, and hasn’t a thing to wear. “I have to get my suitcase together,” the flame-haired singer said at the Yves Saint Laurent show Monday night, rattling off gigs in New Orleans, New York and Los Angeles. Salma Hayek, Claudia Schiffer, Jade Jagger and Hong Kong pop star Joey Yung also took in the show. French actress Vahina Giocante said she just finished an Israeli movie titled, “The Unforgettable,” in which she plays a photographer and journalist. “It’s a bit like ‘Blood Diamonds,’’ she explained. Turns out Giocante is an amateur shutterbug, preferring to snap “surrealist” images.