The histogram reflects underexposure, and it looks underexposed to me as well. When correcting for the underexposure, noticeable noise appears in the image, I'm assuming from using iso 1600. There are parts of the main subject that are out of focus.
I hope that helps!
I also believe if the technical issues are fixed, this would get an IP rejection unless there is a property release.
Read these links.
As @George_F said, the artwork will require a signed release by the artist. When you submit assets to Stock, you're submitting images for commercial use.
El iso tan alto te ha producido mucho ruido, y sobre todo el principal problema es el foco del agua que te a a producido una luz quemada y mucha aberracion cromatica en el agua, esto te pasa por tener una fuente de luz frotal a la camara.
A few things: