omg that's so cute LOL
== MASSIVE SPOILERS ==
yess i can clear up any qs you have! basically the entire time, mimi was living in her head. the first twist is that she runs a taxidermy shop (not stuffed animals) as you can tell from some of the glitching, but then it glitches into a human torso and it's softly implied that mimi was actually taxiderming her lover (domo) the entire time after she had killed her in an argument (all the fixing stuff in the end is when she snaps out of the delusion and sees domo as a dead body). the "customer" is actually the narcissistic side of her talking to her ("it's all domo's fault"). there are 2 endings, the delusion end and the death end. delusion end is the fake happy one where they end up "happily ever after" but it's actually just all her fantasy. she falls more and more into that fantasy to the point where even though she feels that it's a dead body she's kissing (sour taste, bugs crawling into her mouth) she's still like omg but domo and i forever forever! the death end is where it implies that she hangs herself bc she's like "how the hell did i end up doing this i deserve to die" (domo becomes the side of her that hates herself).
lmk if u have any more qs!!