No need to be sassy.

I just found it interesting; I don't really have a dog in this fight since I'm white and I don't feel like my opinion would hold nearly as much water as someone else's. But it's an interesting discussion to have nonetheless.
But as far as labelling and slamming OPs example as "black face" then, with historical examples in mind, it could be MUCH worse and, even if tacky or in poor taste, doesn't seem to be out to offend.
White people tend to cosplay tons of Japanese characters, but because our skin colour is largely the same it's not subject to the same scrutiny.
When I think "bad taste", Mickey Rooney in Breakfast at Tiffany's always comes to mind who's both caricaturized and played up as an annoying and meddling character.