This Lea Michele fan-art contains
demoiselle d'honneur, demoiselle d’honneur, robe de cocktail, gaine, bouquet, corsage, posy, and nosegay.
There might also be
robe de dîner, formel, robe de soirée, formelle, bustier, épaules nues, bretelles, nus, bretelles épaules, and robe.