The lessons are fun and do a good job of introducing one tiny topic at a time, almost unobtrusively. But after the end of the document the lesson is never reinforced. It would be good to see some suggestions on what to do on your own to cement what you learned.
For instance (and these may be good or bad ideas, since I'm not an art teacher): After the Bitty drawing, there could be a suggestion to draw her again, this time without looking at the lesson. Or to change her so she's a boy. Some way to strike out on your own and leave the crutch of copying from the screen behind.