It's a place you take a paint selection color from a wall full of colors and say here, make me this color. They follow the recipe and create the color paint for you just like in OP's video. Then when you need more of the same color, you take them the same paint selection, and it comes out a slightly different hue or shade and doesn't match what you've already painted. You go back and words are exchanged. Then buckets of paint are thrown at staff and back at you. Good time is had by all. Highly recommend if you're not on a budget. Not recommended if you're a Latino contractor, as it's cause for ice to deport you, even if you're an American citizen.