What is the theory behind these mesh of dots that that typically overlay background images/videos?

Here is an example I came across this morning: http://ift.tt/1zsVZ9K

Epic visual tool

Epson 5030UB 2D/3D 1080p 3LCD Projector Submitted October 26, 2015 at 05:52PM by pryme http://ift.tt/1GtxXl5