One of the things that we constantly obsess about is lighting. How was this lit; what were the lighting ratios; was the light soft or hard; If you know all the answers to these kinds of questions you can recreate the lighting of a scene.
Once your lists are set up, put the ball where the model is and take a snap. Since the ball reflects all 360 degrees of a scene it capture any light sources around it. Combined with the fact that it is black it makes it easy to spot any reflections.
Now, you do have to understand light to actually be able to reverse engineer the ball reflections (I strongly advice both strobist 101 and the Light Science & Magic Book for that), but if you can do the reverse engineering , this is away easier that figuring out the shadows.
[Super Geeky (and Effective) Trick to Replicating a Photo’s Light | CreativeLive via ISO 1200]
P.S. into shiny little objects? check our tip about marbles and catch lights.