"homunculus, a Latin word meaning “little man/human." Often the homunculus is shown in moments of Mary’s annunciation by the angel Gabriel: in place of the dove, representing the Holy Spirit, a small image of baby Jesus flies from Heaven towards the Virgin"
Link to information: https://wtfarthistory.com/post/7886097565/homunculus-n-a-little-human/amp
In the ancient world, it was thought that a homunculus is what semen contained.
If it was "planted" in a fertile womb, it would grow.
I had never noticed this aspect of medieval art, however. But it probably reflects the idea that if a woman were to become pregnant by any means, either naturally or miraculously, a homunculus would have to come from somewhere.
