It's a concept like The Purge, without the blood. Or like this 1979 Purdue University study on "wearing masks and deindividuation," without the academics. In short: people do not act the same when they don a mask. They lose their moral compass.

The idea is explored graphically in "Slow Acid," where a female is spray painted silver, top to bottom. It erases her skin, her hair color, most of her defining features as an individual. She acts out, appearing to have mugged someone for their purse, from which she pulls items. Robbing an convenience store. Dancing naked outdoors. The spray paint obscures any signs of empathy, remorse, aggression, tension, whatever we expect to see. Her face is a blank slate through it all, making that possibly the most disturbing thing. It robs her of her humanity.

By itself this is an interesting vignette and morality tale, albeit one that gets a little weird at the end when camera tricks distort her body and the viewer is left to imply that perhaps she was never human after all, but alien in origin. That obscures the meaning some, but is in the tradition of mid-century American and European sci-fi writing.