I met a bunch of young people at what appeared to be a camp, who were treating me like one of their party.
me: "I'm sorry, you seem to be treating me as if I belong to your group when I do not. Who do you think I am?"
them: "Your name is Furin."
me: "Well that's not what I know my name to be. But what's the coolest thing you can show me, so long as I'm here?"
One of them pulled out a "handheld liquid nitrogen generator". It spewed a sheet of some kind of strange vapor.
Note 
The device's function resembled a tiny FogScreen, though ostensibly it made liquid nitrogen:
...and I realize now that maybe they were taking my 'cool' request literally by showing me something that generated a very cold chemical compound.
me: "Can you show me how this works?"
The person showing me the device began disassembling it. Yet his disassembly did not show this device to have component parts smaller than it. As he "drilled down" into the device implementation, it would transform into something large and awkward but that was functionally equivalent.
Note
It's something like having an egg-producing machine the size of an egg carton, but when someone asks you how it works it suddenly expanded into the size of a chicken coop with chickens in it. I've seen an in-dream demonstration of a pen caddy that had a similar character.
I tried to make notes on the design, but it became clear to me that this was not something that was going to be viable in conventional reality.