1 Now there was a council of the priests, and they said: Let us make a veil for the temple of the Lord. And the priest said: Call unto me pure virgins of the tribe of David. And the officers departed and sought and found seven virgins. And the priests called to mind the child Mary, that she was of the tribe of avid and was undefiled before God: and the officers went and fetched her. And they brought them into the temple of the Lord, and the priest said: Cast me lots, which of you shall weave the gold and the white and the fine linen and the silk and the hyacinthine, and the scarlet and the true purple. And the lot of the true purple and the scarlet fell unto Mary, and she took them and went unto her house. . . . Mary took the scarlet and began to spin it.
1 And she took the pitcher and went forth to fill it with water: and lo a voice saying: Hail, thou that art highly favoured; the Lord is with thee: blessed art thou among women. And she looked about her upon the right hand and upon the left, to see whence this voice should be: and being filled with trembling she~ went to her house and set down the pitcher, and took the purple and sat down upon her seat and drew out the thread.
2 And behold an angel of the Lord stood before her saying: Fear not, Mary, for thou hast found grace before the Lord of all things, and thou shalt conceive of his word.
The idea of the Queen of Heaven doing manual labor was no problem to the Orthodox of the Eastern Roman Empire -- they had inherited the Homeric tradition where Penelope--a queen--weaves; Arete, another queen, spins purple; Helen weaves, and spins purple; and goddesses weave.
As images of the Annunciation became more popular in the West where queens did not work and the idea of spinning made no sense, despite what the Protoevangelium said, the wool disappeared, to be replaced by a red book. In church symbolism, Mary represented the Old Testament and the Book of the Law, but she was also literate and of good family. Sometimes she sat to read, and sometimes she knelt to read from her prayer book, and someone has written on the theory that in Florence the size of the book suggested the degree of popular participation in government. Possibly the image of the book was reinforced by the comments in Luke that Mary asked questions and thought about things.
The image of a queen began to drift away and another image began to appear: that of a lady in a bedroom. The image of a woman alone in a bedroom implies the rise of a class of people who were literate and who could afford these paintings--often private devotional images--and the development of the idea of privacy. The image also suggests the affluence of a household that could give over a room to a young woman. The painters were making their statements of theology, possibly they sometimes painted a room in their clients' house, and they were also suggesting that this private room in their clients' home could be a sacred space.
But the bed has another implication--very simple, really--and that has to do with where babies come from. The painters were not arguing with the Gospel of Luke and the Protoevangellium. They and the people who bought the paintings and who said what they would like to see in their paintings were simply being realistic, and possibly the painters were painting the rooms, or rooms like the rooms, in which their paintings might hang. And possibly the annunciation of a baby in a bedroom offered hope that the people who used that bedroom would have their own baby.