The art isn't sloppy tumblr shit designed to look fat and ugly just to make a statement (and to hide the fact that most of these tumblr artists fucking suck to begin with). They don't look like hilariously racist caricatures or MtFtM trannies.
Barrett being not-black also shows that the artist isn't blackwashing because FUCK YT!, and was legitimately trying to do an honest "what if the races were swapped, how would that look?" re-design. Not a hint of bullshit gender about it, either; no genderfluid aromantic demisexual pan-dimensional trans-otherkin nonsense to force the artist's conceited agenda.
It's a combination of non-agenda pushing intent + genuine talent that most of these shitty tumblr redesigns completely lack.