I forget if there was a real reason as to why she's sitting in a goblet/glass thing. I think I just liked the idea of a mermaid in a bath or something but then I wanted it to be see through and as I sketched it out, it started to look like a wine glass... so here we are. My made up lore is as follows: don't leave your wine glass sitting out or else the wine mermaid will take a bath in your glass! Presumably, the lore is to encourage people to not waste wine. Or maybe to keep children from getting a hold of wine and making a mess? I don't know man, I just work here.
Watch me draw this mermaid here:
with love - M