Melusine is a fresh-water fairy, so the aquatic association is natural. However not all artists are consistent, so serpent-like depictions / descriptions do exist. She also flies, so wings are sometimes included, potentially tending toward draconian traits - the dragon flying over the castle of Lusignan. So, perhaps it might be better to call her a spirit or a fairy.
Is she in or is she out? Mermaids are fish-like from the waist down. And generally they stay that way. They don't transition to a fully human form. Melusine does make the transformation, back and forth one day each week.
How might an artist depict the transformation process in a single illustration? By finding a way to show it in mid-process.
Don't forget the de Metz text, Harley 334, which has origins in Paris and has illustrations with cosmic and pond-related connections, and is dated to the same time as the Golden Fleece and the Sainte Hostie de Dijon. (This also coincides with the latter part of the Anglo-Burgundian occupation of Paris and the VMs parchment dates - single source calculation.)
Is she in or is she out? Mermaids are fish-like from the waist down. And generally they stay that way. They don't transition to a fully human form. Melusine does make the transformation, back and forth one day each week.
How might an artist depict the transformation process in a single illustration? By finding a way to show it in mid-process.
Don't forget the de Metz text, Harley 334, which has origins in Paris and has illustrations with cosmic and pond-related connections, and is dated to the same time as the Golden Fleece and the Sainte Hostie de Dijon. (This also coincides with the latter part of the Anglo-Burgundian occupation of Paris and the VMs parchment dates - single source calculation.)