Then comes the front matter, starting with the title page:
I think the dark grey verso page gives more weight to the title page. The cow on the title page also continues the animal theme from the end-paper and cover (the cover features a mouse), without being too repetitive.
Here's a page spread from the book, with a pretty traditional layout. I've labelled the margins in order from largest to smallest (1 being the largest margin). If you don't include the running head, the top margin is larger than the outside margin.
What's most striking about this page spread is the leading - the space between each line is large enough to be noticeable. It's still readable, but I think it's pushing the maximum leading narrative text can have before each line becomes too separated.
The running heads are also notable for being centre-aligned and not closely anchored to the text panel.