Weird illustrations remind me of Edward Gorey, Charles Addams (and Bret Helquist's reboot of these for Lemony Snicket). Its cinematic grammar starts with the 'establishing shot' on the first page and keeps the feel of a movie throughout. Travel is marked like in a 1940s adventure film with dotted lines on a globe. The illustrations of the people are just plain wacky, especially the father. At first, it looked like an optical illusion where you see a face when turning it upside down. But the longer I looked, the more I felt like this was a thinly disguised Humpty Dumpty.
Two spreads drew me in and made me get lost in the illustration--the page with the bats (I love it because it doesn't use the conventional stylized image, but tries out a different one), and the page with the other animals in the woods. This was great, because it was supposed to be a turning point in the narrative. The palette in the spread with the flowers is remarkable because of how it achieves contrast through saturated color on dark background instead of white on dark.
As far as messages go, I love that this book is not so much trying to deliver a lesson through the story as it is trying to ask us 'and isn't that okay'? It's still manipulation (and I'm a night person), but I had to appreciate its indirectness compared to other books with a message.