X-ray box

After selecting a card, the magician shows a little polished aluminum box and takes out a piece of white photographic paper from it. He explains that it is a heat-sensitive paper. The spectator puts the chosen card on his right palm, the box with the paper inside over it, he covers the box with the lid and puts his left hand on top of all. After a few seconds the spectator himself opens the box and he finds the paper printed with a color x-ray image of both his hand and the selected card. Complete, with two different printed photographic papers.