This is a drawing made with light, from certain persepctives the image is hidden and the piece appears to be only a piece of blank paper. But as you pass in front of it the image reveals itself. There is no video trickery, just light.

 

Este es un dibujo hecho de luz, está hecho para que cuando uno lo vea parezca un hoja de papel en blanco y no es sino hasta que uno pasa frente a ella, que la imagen aparece.