This chapter is just dumb.
Guess KT was feeling lazy and just drew whatever in five minutes.
That's a bit harsh. It's just a slice-of-life chapter- that's kind of the point of the mini-chapters.
I actually like these sister-focused chapters with Kaoru and Honoka, no matter how plotless. These interactions are the only time I can find any like for Kaoru as a character, actually. I hate her as a friend and a love interest, but I love how great of a sister she is to Honoka, and just seeing their sister dynamic in general. Considering these mini-chapters never have much plot regardless, I'd actually personally like to see more of these two in them, since there's never enough for a full chapter and they're just little cute, funny moments.