The Annunciation (Madrid)

This diptych is a perfect example of a trompe-l'oeil: an optical illusion. Here it is done in grisaille. It really seems to be a three-dimensional picture.

The stones the figures stand on seem to point out of the list. Mary and the Angel's wing seem to cast a shadow over the list, making it look as if they are standing in front of it rather than next to it. It also seems as if the figures are reflected in the shining black marble in the background. The text in the top of the list seems like cut into stone.

Perhaps Jan van Eyck tried to show the superiority of painting over sculpture. Painting can not only imitate sculpture but also surpass it.