In the context of this artwork, explore the Carmelite influence of the Theories.
When Lippi was a member of the Order of Carmelites, it is told by Vasari that he was captured by barbarian pirates during his travels. Some did not believe this story, but when he returned to Florence, his paintings were famous. He was getting many commissions from the church and they would often lock him in dimly lit rooms to complete them. He eventually escaped, though he always owed a debt to the Carmelite Order. These feelings of having his freedom stripped by the church by locking him away may be portrayed in this paintings by having Gabriel not hand the branch, which according to Old Testament references symbolizes freedom, to Mary, despite her reaching out for it.
Florence Carmelites Old Testament