Diego Velázquez (1599-1660): Las Meninas, 1656-1657.

This famous painting shows classic artistic effects of Velázquez: complex sight-lines, multiple groupings of courtiers, an inset scene and a mirror image (both in the rear), paintings of similar scenes on the walls inside the painting. Museo del Prado, Madrid. See Hugh M. Richmond, 'Shakespeare & Velazquez' in "Festschrift in Honor of Dieter Mehl," ed. Christa Jansohn, University of Delaware, Sept. 2010, pp. 241-52. Picture and some data courtesy of the Yorck Project, under Creative Commons Attribution-Share-Alike License (Wikipedia).