Oscar-winning Mona Lisa Descending a Staircase filmed in 1992.
Pioneering this technique was one-time Vinton animator Joan Gratz. This is a unique technique in which every frame is set and shot one by one to give an animated look to the art. The technique is called Clay Painting. According to Wikipedia - Clay painting animation (which is also a variation of the direct manipulation animation process), is animation where clay is placed and flattened on a flat supporting surface and moved like "wet" oil paints as on a traditional artistic canvas to produce any style of images, but with a clay 'look' to them, filmed frame-by-frame by an animation camera (shooting from above, an in a traditional animation stand) after each small adjustment of the clay images.