The global pursuit of beauty

I thought this piece in the New York Times' photography, video, and visual journalism blog was especially well-done, with stunning and thought-provoking photos. It reminds us that the pursuit of beauty is so wide-ranging, not just in geography and population, but also in what individual segments of society deem acceptable and not. Where do you draw the line between medical necessity/maintenance of health and hygiene/adaptation to social and cultural norms/preening/cosmetic surgery/obsession/psychiatric disorder? It's more difficult than it seems.