Added the tag artistic error, because seems like the artist tried to copy and paste Youmu's faces from their previous works to the four clones in the background, but the excecution was not completely proper. I also managed to track those previous past works the artist used to make the edits, I'm going to post them from left to right.
post #8127689
post #7924358
post #7841299
Fourth clone (Original Pixiv source/Not uploaded here yet).

Fair enough, but I'd guess that the artist may also have been trying to somewhat emulate the very rough and loose style of the music video he's parodying here. Many parts of it look like rough copy-paste operations too.