1. A system comprising: an imaging device to capture a plurality of images of a figure using visible light; a processor; and an output device; wherein said imaging device captures a first of said plurality of said images of said figure in a first position; and said processor compares said first position of said figure in said first of said plurality of said images to a second position of said figure in a second of said plurality of images, and determines compliance with an instruction to change said first position of said figure using said comparison.