Eight pictures, four big and four small, and a two-part color code at the top: big is red, small is blue. A teddy bear, a whale, a drum and a rocket fill their boxes, while a bee, an acorn, a pair of cherries and a heart sit tiny in theirs.
The code is written in words, so a grown-up will usually read it out once, and after that the page runs itself. Each picture only asks one question, big or small, which keeps it well within reach for a three or four year old.
Four of each gives a quick check at the end: count the red ones, count the blue ones, and both should come to four.