There is a long history surrounding how darker skin is deemed less beautiful than white skin. There is a whole system of oppression that makes it difficult for black models, actors, performers, etc. to get work simply because their appearance/race makes them less desirable than their white counterparts.
Dear white people: a race or skin color isn't something you can put on whenever it's convenient for you.
Quoting this again since no one has responded to me yet:
No it doesn't.
A race isn't a costume- just because she did it a little better than most doesn't make it any less problematic. (It still looks pretty inaccurate and bad.)
For a long time, I felt I couldn't get into cosplay because of my skin color because there were so few characters that I knew of that had darker skin. Eventually, I accepted that I can dress up as anyone who I want to be but the stigma is still there.
A white cosplayer darkening up their skin feels like a slap in the face to all the difficulties black cosplayers have to face in regards to racism.
She gets to slap on some bronzer and is applauded as "accurately" depicting this character.
While black cosplayers get comments like "XXX character isn't black. Why are you cosplaying them?" and "This is pretty good even though they're black".