A new genre? Prehistorical fiction? It's really hard to get into the mindset of a prehistorical society. Some of Miller's story seemed interesting and likely, and other bits had the current time written all over them. For example, the 'how was practice today' page made it seem like the boy had just gotten back from soccer. Accounts of cave painting, including Herzog's 'Cave of Dreams' make it seem likely that access to cave painting was arcane and esoteric, not just something mom did on the side to decorate the cave. The sudden cut away from the mammoth hunt was a little disappointing, too. I thought the best next page after "Kali must be a shaman" would be everyone around the fire with a hunk of meat. The idea Kali's music had new and unexpected effects on the world, and that this would be construed as magic, felt right on point.
Composition and design for the mixed media illustrations were pleasing to look at. Handmade paper with cut-out scenes and figures all contributed to a pleasant visual experience. I would say the relationship between words and pictures is what Winfried Nöth called redundancy: "Redundancy is the extreme counterpart of dominance. In the context of a picture, a verbal message is redundant when it only repeats what you see anyhow." [Notice how I used the word redundancy twice in a row?]