" ...a boy in my dormitory said if I develop the film in the right potion, the pictures’ll move ... It’s amazing here, isn’t it?"
-- Colin Creevey (CS6)
If normal Muggle photographs are developed in certain potions, the resulting images will move.
References from the canon
- Colin Creevey discovered this during his first year at Hogwarts. He was pretty excited about it (CS6).
- After the death of Dumbledore, Severus Snape fled to Grimmauld Place where he found a photograph once belonging to Sirius Black which showed one-year old baby Harry flying back and forth on a broom between his father and his mother. Snape tore the photo in half and took the side with Lily, leaving the the other side with James for Harry to find later. Since baby Harry is flying back and forth, he goes in and out of both sides of the photo. (DH10, DH33)