From Zoe:

“in terms of crowd art-
the mass games in north korea-
all the mosaics in the background are kids holding colored sheets of paper.
there is a movie about it which is called “a state of mind”
if you google video or youtube for mass games you can see footage.
it is pretty incredible.
i dont really know if it counts as “crowd art”, but if you like crowd
art you’ll be really tripped out by the mass games.”