My take on it is that the author is trying to use an old satire technique in which what's normal is shown as absurd through the eyes of a total outsider.
This may be a reason why this seems to be popular in Korea, still ongoing at 130+ chapters. This chapter essentially takes a jab at that highly hierarchical society, as in showing the absurdity of discrimination in school based on where one lives. The author is even clever enough to convey it in the art, as when that queen bee girl was talking down to the lower class girl, literally so from higher up in a staircase that resembles the mental one the protagonist kept updating, and using language that essentially places the blame on her. The previous translator, Hamth, did say in a comment that this series is about that kind of thing, rather than an action series.
Personally, I enjoyed the headbutt that crazy hag of a mother got. And am looking forward to the next chapters.