If kids created children's books they probably wouldn't think to include double entendres in the dialog and sneaky little pictures in the background, but they don't- adults create kids books, so they like to include a little something for the parents to enjoy.
Sometimes it's a funny line that can be easily seen as racy by adults but are still totally innocent to kids, while other people have spotted hilarious and purposely inserted imagery like the blocks that spell "hepatitis" above.
This exerpt from the book "Nan's Man" is just plain strange, and the humor seems lost on a little kid, but maybe kids like a good wig and leg wax joke as much as we older folks?
See more Ridiculously Twisted Stuff In Backgrounds of Children's Books at FAILBlog