There is an implicit message in there -- love what you do -- that I didn't see mentioned here (or in the earlier post of this http://news.ycombinator.com/item?id=644796). That guy is not dancing to attract a crowd, he is having a great time and others wanted to join in.
I think the other message may be that once the crowds start flocking over, something has been lost. The majority of the crowd is there just to copy other people... Lots of parallels to online communities + keeping the magic.
I'd also add the corollary:
A lack of social interest/acceptance is not a meaningful critique of whatever you're doing.
Dancing guy was not -wrong- or -weird- to dance; even though he was alone and the recording was likely started to make fun of him.
The vast majority of the crowd showed up simply because they saw a crowd forming.
I used to go to shows, and there was always a Dancing Hippie Guy in the corner, doing his Hippie Dance, no matter what show it was. Voodoo Glowskulls whipping out a driven punk beat? Hippie Dance. Cherry Poppin' Daddies playing some swing-ish tune? Hippie Dance. Fishbone doing ska? Hippie Dance. Los Fabulosos Cadillacs with some latin-flavored rock? Hippie Dance!
I never noticed this before, but at the very end there's a girl off-camera saying, "How did he do that?"
Like you implied, he didn't say "I'm going to start a dance party today"—just doing something in a certain social environment was all that was necessary...
The human mind is a weird thing. Get a bunch of them together and it's even weirder.
