I think most international magazines put more of their own heritage on the covers. Example russian vogue, russians are white and therefore cator to and most of the time use Russian models (not all but most of the time.) If there was an african vogue, they would probably cator more towards african models. It's just what type of models are at the agency in the country. If an agency has a lot of one race, then the magazines or designers may not like the way one of the black or asian or other type of heritage, walks etc. and therefore don't have any more to choose from. The other magazines might have the same idea or might not even think of race when it comes to covers, I'm just guessing.