The first thing that strikes me is the symmetry and the strong lines along the sides of the glass.
The light is very nice, and the colors are great.
But the thing I really like about this shot is the movement in the water surface, and the detail you captured in the surface.
The play of the shades along the bottom of the glass is very nice, and adds an extra aspect to aid the great composition.
Some parts of the bottom of the glass is a little over exposed, but it does not affect the colors to much, and it does not affect the composition at all... so it is actually not really worth mentioning...
All in all, a very nice photo.