I am guessing they have a flourescent backdrop, and then create Chiaroscuro by timing the laser's interactions so that what is lightest is done first, and as the picture progresses the stuff drawn first has time to fade, and the stuff done last is the darkest which allows you to pic out detail in the monochromatic result? And then I suppose they use a scanner and lots of software skills to imput the desired program?
One idea proposed for laser TV was to have a screen with lines of R G & B phosphors that was to be scanned by a modulated UV laser. If I remember right this was put forward because blue lasers with enough output for TV use were so expensive at the time. Then we got cheap high power 445 and this idea sort of died.
This looks very cool but why does it seem like the laser is a small  shape instead of a dot? I think I'm going to have to try to replicate this now with my projector and RGB color instead of just green