If I were him I wouldn't be able to look in the mirror.
I have to put this before I am late for school.
The mask represents how he feels which means he wants to hide and in the chapter "bleeding scream" he is upset that his friend Jack Will and bully make fun of him.
IN this scene the bat is what represents darkness because in the chapter "bleeding scream" they make fun of August and he is in dark times and his friend Jack Will is doing it.
The pumpkin in the slide shows that it is Halloween and this was in the chapter "Halloween" when August was going to be Boba Fett but instead it was too late so he put on his last year's costume bleeding scream.