The Object-Lesson

I liked this book, but didn't get it. The illustrations have a beautiful Burtonesque look to them, and each page in itself is amusing, but I came away feeling stupid / as if I'd missed some cleverly disguised joke running in the background. I don't really know how to rate this book since I did really enjoy reading it, but it's left me wondering what I've missed, and on investigating online it seems that was the intention, which seems a little cruel. Whilst reading up on it I did, however, come across an animation of the book which other readers may also enjoy:
http://www.kuriositas.com/2011/06/edward-gorey-object-lesson.html