Comment by seltzered_

Very neat to see! I've been wanting to make one for ~15 years, one approach to making one would be inspired by a wooden binary counter where each 'pixel' has a gravity latch that rolls out when on one side and triggers a flip for the next adjacent pixel: https://youtu.be/zELAfmp3fXY

Also worth noting this art project: http://breakfastny.com/dot-screen