I'm a sucker for animal stories so it was a given that Mazel the cat would appeal to me, but it seemed at first like a pretty typical historical fiction picture book. Some of the tropes here are old hat: a lonely person whose life is improved when a new pet wanders in, a poor person whose generosity is unexpectedly rewarded by a stranger, and so on. Nothing wrong with that, but nothing unique either.
Then I came to the part where, lacking candles, Misha the artist paints a menorah and adds flames to the candles each night. When he runs out of yellow paint he keeps on going with fire of blue, orange, and red. I was inspired by his ongoing resourcefulness and creativity, his willingness to keep trying in the face of deprivation. While his paint supply does not miraculously increase, I did hear echoes of the Maccabees' perseverance and reward in Misha's story. That's the part that stands out for me, and that I'll remember long after I've forgotten about the cute kitty cat on the cover.
As to the art in this art-centric story, I enjoyed the contrast between the slightly cartoony shtetl scenes and Misha's Chagall-like paintings with their intense colors and blocky shapes. The sepia toned flashback to days gone by was a nice touch as well.