When abundance makes it impossible to keep everything, have your child to choose 1-2 special pictures to keep. The arcs get smaller because the child is using the wrist. There is visual control. The child looks at the drawing until it is finished. Adults however cannot recognize it.
Drawings are symbols of the objects and events that the child has had.
This is an important step because the child is now using abstract thought. The child can see the relationship between the marks on the paper and the symbol or object. There will be distortions in size. Usually the most important part of the picture will be larger then the rest of the picture. The child has naturally changed the grip on the drawing instrument to a more adult grip.