one could make the argument that SOME bikes do...but i can't...even though i want to.

upon closer inspection, i think that bike is actually a regular 26" single speed. if that was a 20", the seat tube would have to be like, 3 inches tall in order for the proportions to be right...and the discs rotors would have to be TIIINY for them to be that close to the hub and still have that much distance between them and the rim...it could be a 24" though...maybe? it's also a weird angle...and i'm not sure if they (y'know, "them") make 20" tubless tires, but i'm also not sure if those are tubless...the rims sure look like it though...meh...it looks cool. and whatever floats yer boat. i wouldn't ride it if it's a 20"er...but that's because i already have a bmx.