It is very amazing. The colors are complimentary, and nothing feelings out of place or awkward. Everything is realistic, beautiful and satisfying to the eye. Even while I am looking hard for something to change I can't seem to find a thing. If ANYTHING at all, perhaps you could try and push the background back a little and maybe add just a little texture to it. I believe that may add some depth in space and perhaps make it look a bit more interesting and perhaps a little less flat. It is amazing though, very well done and thought out.
It really is a well done piece. The absolute only thing that bugs me is the "signature" it kind of covers the piece a little to much, even though it is faded out and everything, i still feel it kind of intrudes in this very classy picture. You might want to reconsider the placement and maybe the font and effects added to it.
On the other hand the colors are chosen well, yet i feel that the background should be dimmed a little more, as in the opacity should be lower. It's almost like it doesn't leave the glass to stand out it almost blends in with the background leaving the liquid to take all the glory, all the spotlight. If that was the intended purpose then job well done if not you should consider a small photoshop adjustment to lower the dominance.
I might be nitpicking but it's the little details that count and these are my general opinions about the finer details. Of course these minor adjustments are also a preference of yours and this might turn into a discussion about taste rather than execution.
-the execution is well done, as far as the photograph is concerned -you might want to reconsider the placement and style of the signature -some borders might be appreciated but are not necessary -you might want to tweak the colors a bit to let the glass and liquid have the main stage rather hurting my eyes with a predominant background
Either way, it is a stunning piece, the impact and motion of it is great and powerful a little bit of post processing is gonna take it to the next level, but i digress. Stunning piece, great work overall, keep up the good work and good luck in your future work. All the love, peace.