Mayu cried because she feel embarassed her behaviour in front of mirror been shown. Yakubo cried because she feel she's a boring person while the others gave an interesting introduction. In episode 10, Rei, younger than her, give her advice to be more confidence on herself. On Kanagawa's case, it's not anyone fault if Rei movement is more interesting than hers. It's variety, whoever have interesting screentime will get attention. You can say they cried because MC's behaviour, but none of their comment is insulting or hurting the members.