Pale with a dark ponytail, Olivier Theyskens, the former artistic director at Rochas, Nina Ricci, and Theory, is fashion’s Pre-Raphaelite poet. Slightly androgynous, slightly Goth, immensely talented, he’s both delicate and dark at once. In this evocative exhibition the Belgian designer creates a dialogue between his work and the museum’s historic textiles and laces. —L.J.