Part of the answer is that in the fashion industry’s parallel universe beauty is in the eye of the lens, and lenses are not Earth mothers. They take no account of diet or bulimia. They just add the illusion of a few pounds here and there, and models starve themselves to compensate. But the scarier, truer answer is that these wraiths are considered so fascinating precisely because they are different.

Designers, often with unwholesomely androgenous personal tastes, are their Svengalis. And fashion editors, with power to shape teenagers’ aspirations, are complicit. But it is young women themselves — real ones, on sidewalks, not catwalks — who time and again confound the hope that beauty can be redefined as curvy, luscious, even healthy.

No law can prevent the use of desperately thin models. But designers love publicity. They enjoy challenging conventional wisdom. Why doesn’t one of them break out from the stifling embrace of the size zero? If they were to start using real-shaped women on the catwalk, they would display their individuality, challenge conformity and encourage real women to buy their goods. It worked for Dove. Why not for Dior?