Overlay drawing on stream

It would be a really cool functionality to have viewers of a stream with certain permission in the server to be able to draw on a stream. This functionality could be set as invisible so some users don't get bothered, but it would be very convenient and even entertaining to be able to doodle on another person's screen.

Some details of the functionality could be: The streamer is able to set what colour, pen size, and the part of the screen a viewer can draw on;  channel setting could prohibit screen doodling, or a specific role will ban a user from drawing on another person's stream; It could also be apart of the new Discord Game Lab project, one would be able to start an activity and then allow other users to join and interact with their screen.