Some of the dresses at the Balenciaga show (DeYoung Museum, through July 4) suffer because they are hung on mannequins that are too small for the clothes. Too small as in too skinny, no hips, no bosom, no shoulders. They look strange, and it's ahistorical. Standards for models have changed in the last 50 years, and many of the dresses in the show were cut to the specifications of the women who bought them.
And there's evidence of this in the show itself: the video room has a looping show of films of Balenciaga's own models in his showroom. They look like average slender women....although one of them has proportions that make her look a bit stubby even for the 1950s. She's short-waisted in a way that would automatically disqualify her as a model these days. Not only that....she has real, visible musculature on her calfs.
I'll add that this show is sociologically fascinating because Balenciaga freely took fashion motifs from all over Spain: from regional clothing styles, from all classes (fish sellers and farmers), from the religious orders. And then he turned them into artworks. Yes, I almost did buy the catalog.