With its companion painting, 'Saint John on the Island of Patmos', this is one of Velázquez's earliest known works. It is also an early example of depictions in Spanish art of the Immaculate Conception, the doctrine that the Virgin Mary was herself conceived without stain of original sin (it does not refer to the conception of Jesus).
She appears here as if in a vision, standing on the moon and with a crown of stars. The imagery is based on the New Testament (Revelation 12: 1-4 and 14) in which the author, Saint John the Evangelist, sees a vision in the heavens of a woman who bears a child and is attacked by a dragon. In the companion painting, 'Saint John on the Island of Patmos', Velázquez depicts Saint John looking up at the woman in his vision.