The invitation, doodled over with a cartoon sketch of Elbaz and a string of hearts, told guests to arrive at La Halle Freyssinet, a massive space in the 13th arrondissement, at 8:30 for the show that would be followed by “d’une fun party.” Guests arrived at the space to find the venue in full birthday party mode: three-tiered cakes and hors d’oeuvres like finger sandwiches and balls of foie gras and chocolate lined the runway.