Without seeing the picture, what I can say is that when I go to African countries I dress like the people there because I identify with them.
I think it’s only bad If you mock them.
Why if people paint themselves as if they were people of type X is bad, but when men dress themselves as a women it’s not bad? That’s contradictory.
What might answer your question is that IF in a country people traditionally paint themselves as X to mock X, then the natural reaction would be to classify it negatively.
But in a country or in a time where people do this out of identification, I don’t see it as a problem.
Morals are specific to countries and times, it’s not universal and atemporal