Details from Katie Hosmer:
When street artist My Dog Sighs finds litter scattered on the sidewalk, he takes advantage of the situation and turns it into artwork. The artist paints faces on all kinds of crushed cans, giving personality and character to each selected canvas. He says he is "drawn to novelty like a magnet, and loves reaching out to touch every person or thing that is fascinated with its newness."
Many more faces here.