When I was here in the 1960's these images were called "the Danzantes" or the Dancers. It was thought they were in dancing mode. Now they know, they are dead. They've been tortured, usually by masculine mutilation. Times were very rough in these ancient towns. Sacrifice was big. If it didn't rain, obviously it was time to sacrifice someone. The hallucinogenic drugs used by the indigenous went all the way to Lake Superior. The more stoned and the more you screamed while being sacrificed, the better the gods liked it. Or so the priests thought.