High on the wall not far from those competition panels is a Saint George in a niche (1417-20). This is the original of a statue that once stood in a niche on the outside of the Orsanmichele (the city’s granary turned church). The niche in the museum is a reproduction of the rather shallow original space in which George stood.
Below the niche is a relief that, kind of like the predella of an altarpiece, tells the story of the Saint depicted above: this is the very first example of the stiacciato technique – a very low bas-relief that provides the viewer with an illusion of depth – and one of the first examples of central-point perspective in sculpture. And, not to confuse you, but the original of this relief is located on the right wall about halfway down the room (a bit lower so you can see it!).
In the center of this panel is George on horseback in the act of killing a dragon and thus saving the princess on his right, who clasps her hands over her chest in gratitude and amazement. The drama of this moment is amplified by the perspective that Donatello creates despite the medium – sculpture – which isn’t (yet) known for this effect.
Look at the loggia, or series of arches, on the right side of the panel and you see how they recede in space?
This is done (a) using the brand new method of one-point or scientific perspective, and (b) using the sculptural technique that Donatello invented called rilievo schiacchiato, or “squashed relief”.
The marble is just lightly incised, as if it were a piece of paper.