- Your brain has been trained extensively to recognize faces / people. Even very small babies can do this.
- Your brain processes a large amount of mostly noise, and sometimes mislabels noise as objects, which trends towards face-like things (see: seeing faces in clouds, people in shadows etc.) Various classes of substances make this effect more noticeable (even stimulants, including caffeine)
- The jump from that to 'elves' is largely just cultures have some form of small magical person.
I like that coffee is clearly a drug, a mind-alterer. But it's mostly harmless so it's been boosted as a sort of society-wide mascot. Humans really love drugs.
It gets the visuals accurate, but the experience includes a lot of physical sensation that is very difficult to convey, e.g. the 'wind' that pushes you back and the discomfort of going into a chaotic dissociated state. You see those things but it feels very 'real'.
I can only speak for medically-administered intravenous Ketamine, but I would describe it as like relatively effortlessly floating inside of the non-physical space inside of you and meeting yourself in metaphor, all the while completely aware. The biggest risk seemed to be temporarily becoming a relatively inanimate part of the infrastructure there, and even that was a sort of pleasant and satisfying state.
I had a DMT breakthrough experience and was able to communicate, via something like Neuralink, to the entities and for me they did not look like machine elves, but rather some type of alien (a bit like species 8472).
Lilliputian hallucinations are also common in mental illnesses with hallucinations. Definitely some kind of physical foundation for it in the human brain.
I wonder what the brain is doing…