This sounds like a variation of Machine Elves -- https://en.wikipedia.org/wiki/Dimethyltryptamine#Entity_enco...
Those are primarily associated with DMT (the one time I tried it, I too had such an encounter and I didn't know it was a thing until years later).
I'm sure I'll be corrected on this but I think DMT and Psilocybin ultimately affect the same pathways so it's just more evidence that Machine Elves are real! (/s on the real part).
>“It's not psilocybin that's giving the L. asiatica mushrooms their lilliputian effect”
Unknown compound ATM.
The mushrooms that the article talks about do not contain psilocybin (it's still not clear what psychoactive compound they contain), but you are correct in that DMT and psilocybin, at comparable doses, have extremely similar subjective effects.
They are both serotonin analogues, but they definitely yield different experiences.
In chemistry it often only takes a single atom difference to totally and radically change a molecule's properties.