The Met gala has come and gone in a brief cacophony of internet clicks. Like many people, I balance ignorance of its purpose (it’s an annual fundraiser for the Met museum’s Costume Institute) with needing to know what everyone wore. The men triumphed this year, what with Taika Waititi’s unstructured bluish-grey housecoat, Bad Bunny’s seductive white backless blazer, Barry Keoghan in retina-sizzling electric blue plaid and Pedro Pascal’s bare knees, cheeky scout grin and scarlet overcoat. Every Met gala has a theme, and this one honoured the late Chanel designer Karl Lagerfeld. Lagerfeld’s designs were peppy and sellable. But the...