1. Mamarisa: "Alright, everyone. Now you start training your easy smile (act)! "Anyone who doesn't follow the Mister Sequence will get punished like the bean paste-for-brains they are!"
2. Mamarisa: "Start now!"
(left-to-right order) Alice: "Ch-" Marisa: "-a-" Alice: "Chake ich eajy! Chake ich eajy!" CanMari:"..." Alice: "-Ea-" Marisa: "-jy!"
writing on can: "Mackerel"
3. Alice: "YUWAHH-!" Mamarisa: "Now you get punished!" "We don't need any Misters Bean Paste-For-Brains!" sfx: "Yu! ♥" (x2)
4. narration in corner: "Many Practices Later..." Alice: "Awish's schitty-shect fashe-!!"* Mamarisa: "Well? Have you got it yet?"
sfx: (except for the ones I note specifically, they're all "yu") next to CanMari: *wobble* next to marked Alice: *soaked* top left: "Eajy~ Eajy~"
It's just saying that she messed up so much that she was completely covered in ink. I seriously doubt the artist meant anything more than that; remember that Japan doesn't have the social stigma attached to blackface that we do.