I have a nephew with Down Syndrome, and I once sat beside him and drew pictures.
I don't get to see him too often, but the last time I spent a few days with him, I showed him how to draw a building with windows and doors. He understood the idea right away.
Drawing unlocked something in him. Each morning, even before he had his breakfast or listened to his favorite music, he needed to draw a tall building and fill it up with windows.
I'm not sure exactly what drawing buildings meant to him because he couldn't verbalize it. But he reminded me of what a powerful experience it is to create a world on a piece of paper.