I've tried to dig for an answer here in the help center, but no luck. Maybe someone here in the forum can tell.

Please see this article for reference: https://support.khanacademy.org/hc/en-us/articles/115000780012-Guide-to-Assignment-teaching-reports

Then, search for the text "This report is meant primarily to help identify misconceptions!" to see the screenshot I am curious about. At the right side, there are three tabs: "Responses", "Draw" and "Hints". What that "Draw" tab is about? I thought that is the place where teacher could see whatever the student has scribbled with the drawing tool while solving their tasks. But my tests don't confirm this assumption. So what is the function of that tab?