One of the most iconic interior views in the history of art, Velazquez' Las Meninas 1656. Variously described as the 'Theology of Painting' or the 'Philosophy of Art'. There are very few paintings that so directly question the point of view of the viewer. Are we in the shoes of the King and Queen as they pose for their portrait? Every aspect is shrouded in ambiguity, what is the subject? Where are the mirrors? Must Velazquez have been outside his own painting and placed in later? Interestingly the painting was painted for the room that is depicted. As Velazquez was the curator of the Royal collection at the time, he was in a way recording that role and perhaps drawing on another of the paintings in that collection Van Eyck's The Arnolfini Marriage.
Picasso was obsessed by the painting and made many studies of it, some shown above. Also above is an empty version created by Bredan Whelan at UCD, an empty stage set of a sort... An excellent and passionate analysis of the painting is in Laura Cumming's A Face to the World. A rich and readable book on self portraiture.