It looks like you took the picture in low light, because of the graininess of the purplish background. Maybe you could work on better lighting. It also helps to use a tripod or some other way to steady the camera to get better focus. You also can use post-processing to "fix" a grainy picture somewhat (e.g. NeatImage), although you have to go careful to not overuse it as you end up with bad results.
As far as composition, it might have been better to just photograph the two bottles (no caps, no ruler, no strap). A slightly different angle (from above but a bit to the side) might also have worked better. "From above" can be very dramatic, but sometimes it's not the best choice to go straight from above.
OK, a fizzy liquid. It's not too recognizable down in the bottles. Also, the phot is very pixelated and noisy. Because of that it's hard to tell, but the focus doesn't look very sharp. Not sure what the ruler is there for. 3
Way too low res. Massive pixelation all over. This needs to just be taken a lot closer to say the least. THe composition isn't that strong either. I don't get the ruler thing at all.
I find the upper left corner a bit distracting. What is the ruler for??? I think it would have been neat if you'd shook up the coke and photographed it spilling over. I like the purpleish background.