Head dancers are respected individuals invited by the powwow committee to lead grand entry and dance throughout the powwow. Money was placed at his feet to honor. This was the head man dancers special. His way of giving back to the powwow to show appreciation.
I didn't see him picking it up. Whatever they get tossed at their feet goes to the arena director for spot dances or sone charity. Also "traditional" is just a name. Like the federal reserve. The people who make the U.S. currency have nothing to do with the government. Not to mention. Making the regalia is expensive as hell. To get to the pow wow costs as well. Plus most of these are spectacles. "For educational purposes." To remember the ways in a celebratory fashion. This is not a true spiritual endeavor. Or else cameras would not be allowed. So yeah money is incentive to the dancers. Not everything natives do is supposed to be done for free. Like I take a dump at work so I get paid for my sh!t. It seems yours is free and comes out of your mouth.
I don't know THOSE people but, some people I know make stops at pow wows for spiritual endowment and community representation. At quite a few places. Where there's no electricity, no MC, no contests. Just a gathering of people who want to dance and sing. Most of which don't get advertised and one would have to have an invite. Also when I danced. I never registered for the cash incentive. Anyway why ask me? I'm just "some fnck crying around on the internet." Why not ask your people? Your elders? I assume no matter what I say. You ain't believing anything.