So, firstly, I'm no expert. And secondly, I think I know what you're getting at. However, calling the representation 'androgynous' is a bit odd, if the definition of androgynous is to have characteristics of both the male and female genders - when, in the given illustration, basically, there are no representations indicative for either sex. Of course there is a general reluctance on the part of many medieval Christian sources to depict genitalia. So this results in a neutral, asexual person, who is probably male if there are no breasts. Besides which, the image derives from the narrative, not the other way around. But then you also need to know the narrative. Of course, Jonah is an obvious choice, given the provenance.
What is less obvious at the start of the 'Merpersons' investigation was the difference between a generic mermaid and the historical mythology of Melusine. Not to mention drawing a clear distinction between the dragon version of Lusignan and the more mermaid-like version of Luxembourg and the Valois. For the VMs mermaid, one clue to her identity is supplied by the recovery of the Melusine narrative.
What is less obvious at the start of the 'Merpersons' investigation was the difference between a generic mermaid and the historical mythology of Melusine. Not to mention drawing a clear distinction between the dragon version of Lusignan and the more mermaid-like version of Luxembourg and the Valois. For the VMs mermaid, one clue to her identity is supplied by the recovery of the Melusine narrative.