These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Alternative Character Interpretation: Is Mala an unreasonable harpy only out to get Vladek's money or a sympathetic character trying to cope with the miserly and demanding Vladek? Vladek certainly subscribes to the former, but Art (and most readers) drift toward the latter.
It doesn't help Vladek's case that we never actually see any of Mala's "I WANT ALL THE MONEY" outbursts, only hearing about them from Vladek. It could be possible that she simply didn't act like that in front of Art, but it is far more likely that Vladek was being his usual miserly self.
Crowning Moment of Heartwarming: The family in Hanover that Vladek and Shimek meet after the war. They are given a warm welcome by the German Gentile wife, her Jewish husband whom she hid during the war, and their two children - cat-striped mice. Seeing this obviously loving German-Jewish family unit for a few brief panels is a welcome reprieve after two volumes of cruelty, and serves as a little bit of proof that the Nazi ideology, ultimately, didn't win.
Jerkass Woobie: Vladek is the incarnation of this trope. He was extremely cheap, drove his wife crazy, verbally abused his son, and was racist. However, he did go through the Holocaust and then after that his first wife committed suicide.
However, Mala points out that she is also a Holocaust survivor, as are many people in their neighbourhood, and none of them are like Vladek, making it debatable whether it really is Vladek's terrible experiences that make him such a pain.
At Auschwitz, when the bodies were pulled out of the gas chambers, they were pushed into ditches and set on fire. Not all of them were dead.
That doesn't sound as bad as being buried alive. Not everybody had a chance to die, or even get shot, before they were thrown into mass graves.
The four hanged women. There's a scene in the present that's drawn as if they're hanging there, a sort of flashback.
The comic Art makes about his mother's suicide is this mixed with Tear Jerker.
The countless times Vladek tells of someone who he knew, was friends with, had a plan, etc and after they parted ways they were never seen again.
Tear Jerker: The ending to the second book (and thus the whole story), one of the most powerful moments of the story, when Vladek slowly goes to sleep and tells Art goodbye... but addresses him as "Richieu", which gives more fuel to Art's previously mentioned feelings that his parents had always loved their dead child more than him. The next and final panel shows Vladek's and Anja's tombstone.
There is a moment near the end where Anja sees the picture of her living husband. Only it was no mouse, it was an ACTUAL photograph of Vladek Spiegelman, a man, a human. It is a simplistic, yet powerful reminder of what the Nazis failed to see.
There is also a photo of Richieu in the front of volume II, and one of Anja and a young Art at the beginning of Prisoner on the Hell Planet completes the inclusion into the book of photos of Art's entire immediate family.
Near the end, there is a story told to Vladek about a Jew who survived all of the Nazi atrocities and attempted to return to his home, only to find that Poles had taken it for their own and are very unhappy to see the rightful owner return. With no idea what else to do, the Jew sleeps in a room behind the place. The Poles find him there and beat him to death just for the fun of it.
Tough Act to Follow: Art Spiegelman has been quite vocal about how he never expected the "monument to my father" to become so popular, nor did he expect that his later works would be greeted by wishes for Maus III.
Values Dissonance: Despite having been a victim of what was probably the worst case of institutionalized racism in the history of mankind, Vladek has a few old-fashioned ideas about race and class.
This is Truth in Television for many Holocaust survivors - Hannah Arendt, a survivor, makes this point specifically: Why would people think the Holocaust is a learning experience?