What happens if you give a bunch of hackers the ability to change pixel colors on a beamer screen? See yourself :)
p1xelflut uses a very simple (and inefficient) ASCII based network protocol. You can write a basic client in a single line of shell code if you want, but you only get to change a single pixel at a time. If you want to get rectangles, lines, text or images on the screen you have to implement that functionality yourself. That is part of the game.