P.S: I have emailed Mattox informing him that I was using his image, and sending a link to this competition, also made a note in his comments

great perspective and idea.
very nice
in my humble opinion, I would have kept the white color of the water flowing, a little lighter.
In any case, nice work
bravo

Love the mood of it

really nice

Good blend & lighting.

rubbing the edges of the cut out with the blur tool might get rid of the sharp cut out effect and make it look more real , but it's a fun image

Needs a shadow. See shadows on posts for reference.

The background is sharper than the model. A quick gradient lens blur would make the model pop more. Good luck!