Background feels empty and could use a little bit more detail, even a road sign of any type would be better than what you've done alone. The sky makes me feel weird, like, is this supposed to be cloudy and if so couldn't you have shaded things a tad darker? The roadside is fine but I'm not sure what to make of what's in between. Mountains?

Undine looks pretty damn fine though, though that one nail from her pinkie finger bugs me the more I focus on it. 10/10 fish tits though.

P.S. Either way those cuffs are swinging they'd probably hit her face.