The Lytro camera is a plenoptic camera, or light-field camera. It uses a series of lenses to extract depth information, which allows the user to snap a picture and then refocus as needed after the picture has been taken.
The perspective shift feature, according to Lytro's press release, "lets Lytro photographers interactively change the point of view in a picture after it has been taken. On a computer or mobile device, viewers can move the living picture in any direction – left, right, up, down and all around."
You can play with the original picture here: https://www.lytro.com/camera#perspective_shift