"Velázquez's Las Meninas has an extremely complicated, highly unusual composition, making central use of a mirror. The artists is facing the viewer, and part of the back of the canvas is visible on the left side. A mirror in the middle shows the two principal persons - the King and Queen - surrounded by the Court, including the Infanta. But where are the King and Queen? They should be with their backs to us in the centre of the picture - but they are not there. So evidently their mirror image is imaginary. Although the mirror is huge for the time (and it is known that Velázquez owned a number of very expensive mirrors), its image is rather small to be fully dramatic."
Richard Gregory, Mirrors in Mind, W.H. Freeman at Macmillan, 1997