1 Galatians 3:13. See also Romans 2:1-29.
2 I am fairly confident in saying that there is no dove in the painting, but it is conceivable that a vague patch of white in the lower left of the sky could be intended as a flying bird:
Titian
The Malchiostro Annunciation
1520
Malchiostro Chapel, Treviso Cathedral
This painting uses light and shadow to delineate the startling irruption of the divine into our world. Gabriel rushes excitedly into an area bathed in light, hailing the Virgin. She has been sitting with her back to the light, a closed book in deep shadow on the floor before her, but as she makes a half-turn toward the angel the light bathes her head and heart.
Meanwhile the donor in shadow watches from afar, mirroring the viewer standing at the entrance to the chapel. The effect is to introduce what the exegetes called the "moral" level of interpretation, in which one applies the action presented in the literal, historical account to one's own moral condition. In this case, the viewer of the present day is invited to reflect on their own darkness and to turn like Mary to the light of grace.
Books are common in other Annunciation images, inspired by the Gospel of Pseudo-Matthew's statement that Mary often spent her time "searching the Law." The other images assume that she was reading prophecies of the Incarnation, and they place the book in her hands or on a prie-dieu. But here the book is on the floor and shrouded in darkness. Thus it represents "the Law" that implicates the curse from which St. Paul says Christ "ransomed us."1
In the deepest shadow of all is the veil of the Temple, just visible on the left of the frame, where the priests of the Old Law entered to "serve unto the example and shadow of heavenly things" (Hebrews 8:5a).
Light and shadow, then, are the artist's way of expressing the coming of the Savior into this darkened world. He also uses this symbolism to render the angel's statement that "the Holy Spirit will come upon you and the power of the Most High will overshadow you" as a flood of light emerging from behind a dark cloud. This is a sharp departure from the tradition of picturing the Spirit as a dove and the Most High as the face or hand of the Father.2 Indeed, the very novelty of Titian's invention is itself a symbol of the upheaval consequent upon the Incarnation.
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Read more about images of the Annunciation.
Read more about light symbolism in Titian.
Photographed at the cathedral by Richard Stracke, shared under Attribution-NonCommercial-ShareAlike license.
NOTES
1 Galatians 3:13. See also Romans 2:1-29.
2 I am fairly confident in saying that there is no dove in the painting, but it is conceivable that a vague patch of white in the lower left of the sky could be intended as a flying bird: