I think they were mocking Akishita because she sweats a lot, right? Like, you should cover yourself with a blazer cuz you smell.
Also, am I the only one who felt uncomfortable with the detail of little Ririka's peeing? Like, the first panel of that page would have been enough, but that second panel zooming in feels too much.
I think it's like Manchura wrote, this closeup was from sister's POV to show that she has some creepy sadistic hangups or fetishes, or maybe she's some kind of siscon.
MC is so fucking useless it's infuriating.
The girl protecting her was obviously hurt by those comments and yet she just stands there and doesn't offer any comfort even after they left.
Maybe because her sister is fucking scary, given the flashback to seeing her bully being literally kidnapped for revenge, and MCV herself clearly has many issues, including communication issues? MC is useless because she's not only some kind of autistic or something, given the reaction of the other kids, but by now also deeply traumatized both by bullying and by her sister's sadistic streak. She just was not only almost bullied simple for being the prez's sister, but also was prepared that the sister would doi something horrible to those girls as well, which she could see as her fault just like what happened two gyarus' , and now the innocent girl that tried to help her was also victimized because of her.
MC is not only shy and asocial, possibly autistic, but also traumatized and in increasingly fucked up situation which seems to be going even more wrong just because she's there. If she tried to do something, assuming she could even find the words, it could end up with getting her sister involved which would just make everything way worse.