>>1789216I'm an artist and I can already tell you now that whoever made the image you posted has a very good understanding on art fundamentals. This is more of a digital painting that editing an existing image.
A few things I noticed: Subsurface scattering on the skin which he made more visible on the painting than the reference.
He/she did a great job with the reflected blueish lighting from the water. More detail and saturation on the face which is the focal point. And a lot more but too many to point out.
I'm sure this particular artist can make quality images like that without looking at any references. Like starting from a blank canvas, starting from scratch/sketch. The artist simply liked the composition and made an anime version of it.
I progressed so much with my drawing/painting in the last couple of years but I still have a lot to learn. I actually have the version of the anime painting saved in my one of my folders but this is the first time I've seen the reference used.
Here is my art page:
http://carlo-marcelo.deviantart.com/