Dear Sophie -
DIEGO VELAZQUEZ was a Spanish painter, the master to GOYA and the beloved court artist of the King (1599-1660).
His great masterpiece is his painting LAS MENINAS. Check it out. He is playing a lot of games with illusion. There is a self-portrait of himself at the easel, the King and Queen are reflected in the mirror, (bringing them into the frame as if they are standing where we are?). Look at the doorway where someone is entering (or departing) the room as if a snapshot of a moment. It also expands the frame implying another space beyond it.
Pre-dating photography it is a snapshot of court life.
This VAN EYCK painting may have been an inspiration. (Flemish painter 1395-1441)
With love,
Mom