One thing I’d suggest to easily enhance the composition (if you meant for this to be an art piece, that is) would be to let the chain fall naturally onto the table using rigidbody physics. It would break up the smooth line you have now (following a curve I assume, which is a fine way to position the chain before letting the physics animation fly), and would be a big step toward selling the realism.
Another good tip for composition (I don’t know any less clumsy way to say this) is to never allow two shapes to come really close together (on the 2d plane) without clearly intersecting. By this I mean the chain that’s sailing right around the shapes of the watch, and just a little bit by the screwdriver head. If you’re not sure what I’m getting at, imagine if your shapes were just filled in with flat colors (like shadeless materials). You wouldn’t be able to tell if the chain were behind, near, or in front of the watch.
I also like to take into account the borders of the image when considering this “rule”: in this case, the bottom edge of the watch and the clip on the end of the chain are the offenders. If you take my meaning, all of your other shapes decisively enter and exit the frame, but the edge of the watch and the clip can’t seem to decide if they want to be in the picture or out.
I hope that made some sense. I know I’m very bad at explaining these concepts in words! If you’d like, I’d be glad to scribble over your image to illustrate.