The artist is from Brazil and of a lower middle class background, which is reallly quite poor by US standards. He mentioned that if something had happened to one of his parents, he could have been a picker in Gramacho instead of becoming an artist.
He blew up the photos on the floor of this warehouse studio in the Gramacho and "painted" the images with recyclables and then photographed the installations. The installations themselves were the true works of art and the proceeds from the sales of the photographs when to the people in the images. It was truly an amazing tale.
I recommend you see the film. Humans can be so strong when it comes to survival.