Four rows, each with the same picture drawn three times at three different sizes: mittens, flowers, fish and dump trucks. The child finds the smallest one in each row and colors it in.
Three sizes is the step up. With two pictures, big and small are simple opposites, but with three a child has to compare every picture with the others, and the middle one is neither. It is an early brush with the idea of smallest, which comes before bigger and biggest.
The smallest picture moves around the row, sitting in the middle, on the right and on the left, so a child cannot just color the same spot every time.