This is some real antimemetics stuff here :) (https://scp-wiki.wikidot.com/antimemetics-division-hub if you're not familiar)

Yeah the mushrooms are obviously an amnestic that lets you see the elves which are usually antimimetically cloaked.

Amazing rabbit hole, thank you for link.

exactly, the real question is what the elves are doing while they’re unseen.

We should've asked Terence McKenna...

It could be a subspecies of the "machine elves"...

This was my first thought as well. I've always been fascinated by written accounts of DMT triggering such oddly specific effects for users.

They keep the universe running.

I can answer the what, that parts easy!

The real question is WHY they keep stealing my underwear and left-foot socks?

Making toys, caring for reindeer, sleight maintenance, ...

And spook work for His Jolliness' Secret Service, to keep their Naughty and Nice databases current.