It is more likely to that these drawings we're done after the artist came down off the drugs (but most likely just after reading about them. These pictures are

It is more likely to that these drawings we're done after the artist came down off the drugs (but most likely just after reading about them. These pictures are clearly a conscious drawing of how people think about the drugs, not the product of a brain and hand under the influence). On nitrous, he wouldn't have the muscle control to draw the picture. Compare to the famous set of pictures drawn by an artist on LSD.