Sensei's at that part of her mental health struggle where she's beating herself up for not getting better and just trying to brute force through it. Pages of black spirals just trying to draw something and throwing herself up a mountain to the point of complete exhaustion. Also explicit confirmation that body image issues are at least part of her troubles, not that it was too hard to spot in previous chapters. This is rough to watch, I really feel for her.
I couldn't put together why she bought the tamagotchi phone until this chapter, but it was probably to get away from the online criticism. Her reaction on page 33, grunting in disgust, punching the bag, and bracing herself before checking the message, must be leftover reflexes from being stuck in social media hell. Twitter comments were killing her, but she couldn't stop herself from obsessing over them.