[Nymph Philosophy] Why the nude female form?

[Antonio García Jiménez]

The example of Christine de Pizan is always worth noting, but I am more inclined to point out her use of allegory. In La Cité des dames, the personification of Justice, Reason and Rectitude help her to build the city. This allegory, the personification of
virtues or abstractions, is something widely used at the time.

  I think the nude ladies of VM are a personification of astral spirits that come down from heaven to fertilize the Earth. Her nudeness is a symbol of fertility. They carry the water that makes the herbs grow, that's why we see them bathing in the pools and leaving the complex pipes of the universe