PARIS — At first glance, this was a high-end, high-profile auction just like any other: held in the sale room of a gilded mansion near Avenue Montaigne, with an enthusiastic auctioneer, a sea of fierce bidders, prices ranked in euros, American dollars, Swiss francs and other currencies, and harried-looking staff members monitoring telephones and online bids.

However, some things were different. For one, the bidders were mostly young and urban, wearing baseball caps, hoodies and sneakers. A Chinese couple sat hand in hand on the second row, catalogs on their laps — she in a Gucci T-shirt, he in a Louis Vuitton denim jacket. Behind them was a serious looking man with diamond earrings, immaculately trimmed facial hair, wearing a Supreme x Undercover jacket. Behind him, gaggles of teenagers in rhinestones, plenty of whom still had braces on their teeth.

Largely French, but with a scattering of Chinese and Americans, few in the registered crowd were likely to have been to a traditional auction before. But then the works going under the hammer weren’t exactly old masters.