This is suffering from a few things...firstly, there's a lot of noise in the photograph and it's lacking any focus. Compositionally, this could benefit from a few things, but the biggest is the glass itself. Hard to get the gist of orange juice in a blue cup. :)
for some reason this photo seems to be very grainy! i'm interested to see what type of camera your using because that may be it! if i were you, i would have cropped it back to take out more of the distracting shirt.
This is a nice composition, but a bit grainy. Also, there is a bit of "background noise" (i.e. flora on wallpaper in left behind head) that competes for attention from the viewer.
I would think about using a clear glass/cup so the orange juice looks yellow instead of green. You have a good looking subject with your OJ so maybe more of his face and less of his shirt would be more complimentary to your photo, although your composition is pretty good. There is potential here, just a little more work and attention to focus and you are on your way! Good Luck!