[Nymph Philosophy] Why the nude female form?

[Someguy]

If the nymphs were a representation of the soul, or of geographic locations like Linda puts it, then why did the VMS author(s) use the Balneis or Taccola's diagrams to draw inspiration from? Why not just... draw some random baths? Why the need to copy bath designs and river diagrams specifically from exceedingly rare books, such as De Ingeneis?

Makes no sense to me, if water/bathing was not specifically the objective.