I just got mine and I noticed what looked like a little LED through some clear plastic, in the hole where the keycap sits. I wound up accidentally popping the black tray bit out (whoops -- super glue will fix it right up) and noticed what appeared to be a coil of wires. On a hunch, I plopped it on a wireless charger and -- surprise! -- it's an LED. It blinks.
How was this aspect not mentioned in the description? It's frickin' sweet.