So to update, I did in fact do something back in October; specifically, a tiny infinity mirror. The biggest hangup was my own fault; decrementing an unsigned int so that it looped around and my LEDs didn't behave.
I used a WS2812 LED string. And added someone else's library
for the purpose, along with Webbotlib.
I used a small convex bike mirror, so it was not a true infinity mirror. To do tinting, I used two layers of antistatic bagging from a motherboard's packing materials...
The glass and bezel came from a small clock (which conveniently fell to its death a few months prior). The pumpkin required my going outside to acquire...
Oh, and a cruddy video from before I found the unsigned int overflow bug; I had 12 LEDs before I acquired an extra one (these were all free from a generous coworker), and candles behind the LEDs for awesome effect!: Infinity Mirror Pumpkin
Images below: final board-less 8-pin socket with soldered on caps, crystal and pins; daylight shot; First test with a large mirror; pumpkin with companions at a pumpkin carving party.