Here some remarks about this great image :

1. The pink marble texture used on the floor
   around the pool is somehow strange. Either it's
   at the wrong scale or it's not reflexive enough,
   but it doesn't look realistic.

2. The column in front of the camera is a bit
   disturbing. As it is not a core element of the
   composition, I would remove it or replace it
   by something different(a statue, a foutain, etc...).

3. It would be nice if we could see more clearly
   the reflection of the woman on the water. a little
   change of the camera angle could do it...

4.the light is too homogeneous. A few spot lights
pointing towards different objects will add some
ambiance and mystery.

That's it,

hope it will be useful

Eric