Aww, poor cat is missing the board with his pointer! This is a really funny image and is done well also. I can see a couple areas of what would be, for me, improvement: centering of the text, a bit more realism around the nap-supper-stretch note and the top-right picture (I like the cartoonishness of your image but as you added shadows to the main cat (and did it well, I might add) then I would have liked to see the shadows or a bit more 3-D in the other areas to match, that or just remove the main shadow so it's all kind of flat.)
I think you did really well with the cats in the foreground and the diagram of the can opener is just priceless! I know I had a lot to say about "improvements" but you did a good job.