At many very upscale stores the doors are locked all the time. The staff has to see you through the glass and determine whether they like your looks before they let you in to shop. In many cases if you don't look like you can afford the merchandise, they won't let you in. This is true in Manhattan, Beverley Hills, Palm Beach, London, and Paris--probably some other places too. My suspicion is that if Oprah was not all made up and styled the sales staff might not have recognized her and just assumed she was an ordinary black woman. After all, if they don't watch daytime American TV, how would they know she's one of the richest women in the world and could afford their goods? There were reports that they had been having trouble with North Africans (= blacks) committing crimes in the area.
It's somewhat unclear what the facts really are here; I'm inclined to give Oprah (whom I think generally silly) the benefit of the doubt given my experiences with the French.