A clear cage of live butterflies stood at the center of Roberto Cavalli's runway. Daniele Cavalli, who now leads the house's menswear efforts, loves an animal spirit, and for Spring, he chose the butterfly, icon of transformation. He traced the progression in the runway looks from caterpillar to cocoon to full-on glitz and glam.

Glam being the operative word. "A new glam, a chic glam—that was my goal," the younger Cavalli said backstage before the show. "For me, glam is not only glam rock. I thought about how Cecil Beaton, in another field, was glam, too. For me, glam is a kind of feeling of sexy but in a really masculine way." The tailoring in pastel metallics (Full Metal Jackets of a particularly un-Kubrickian kind), glowing with the dark shine of a butterfly wing motif, or eventually, at the apotheosis, covered in glitter, said "glam" quite clearly. If they added "masculine," it was in a whisper.

The step forward for the season was the new jacket silhouette Cavalli pioneered, one inspired, he said, by the ease he feels when wearing a double-breasted top open—something he replicated in single-breasted versions by moving from a structured shoulder to a looser construction, angling the bottom on the bias for an almost cutaway look.

But see it once and you saw most of what the show had to say. The Butterfly Effect is sometimes used to describe the monumental impact tiny changes can have on the world at large. But at Cavalli, it seemed the effect was more subdued. And at center stage, it was hard not to notice that there wasn't much action in the cage, either. When Papa Cavalli came out with his son and wife for a bow, he flapped his wings. But the butterflies were still.