“Royally opulent silhouettes appear from between the columns of the Palais Brongniart,” Elie Saab’s program announced. But that’s only half right. It wasn’t the silhouettes that were opulent; by couture standards the construction of the gowns was quite simple. Corseted bodices were far outnumbered by softer, draped styles, and the designer opened with what was essentially a floor-length T-shirt dress, albeit in tulle embellished all over with crystals.