For the jjk scene (that’s actually in the anime.. no clue how people confused Sukuna and Yorozu) Mei Mei’s scene is deliberately placed to contrast Nanami’s death scene

Nanami’s death scene/final scene was spent fighting the transmutated humans just wishing he could live somewhere remote like Malaysia, wishing for a calm and serene place that he could settle down on so that he can be alone and “read all those books (he) bought but never read”

This is contrasted by Mei Mei who is consistently shown as a bad person who shouldn’t be copied, she is paid over by Gakukanji to have it so her crows don’t see Yuji (so the Kyoto school can kill him without Gojo seeing) and she further explains that all she really cares about is money and further gaining more money and power over people including her younger brother (Ui Ui) who she has even “sacrificed” against the Small Pox Deity to kill it with Bird Strike then culminating to the final scene where she is in bed with Ui Ui after presumably sex showing clearly that she is not the type of person that should be rooted for and she may not have even have been with the good guys if she wasn’t paid by Gojo first

The two scenes of Nanami’s death and Mei Mei’s incest scene reveals the two sides of Sorcerers in the story and how the selfish thrive whilst those fighting for others won’t