Post Seminar Maus Question

Our seminar was pitifully short. This book was pretty straight forward to me, so I didn't have all too many questions at the exceptions for the masks. I feel that we heard opinions to justify the uses of masks, some better than others, but I definitely saw that we didn't reach a conclusion with those opinions and that we really left it there. I personally have no real clue what the masks mean, though I am sure they are significant. I have a few ideas, but nothing concrete. This issue definitely could have been addressed better and more effectively.