I agree that this was shot in front of a white background. However, we have done similar things with highly reflective objects on green screen. As Rick noted, keeping a good distance from the green wall is important. In this case I'd go for at least 15 feet. For the reflections, since this would be an easy matte because you don't see the floor and the shot is so tight, a 4x8 sheet of foam core on both sides just out of frame, (or in frame as long as her body doesn't cross in front of the card), and possibly another angled up in front on the floor would hide the green and reflect the appropriate white. The white card also helps to bring detail to the black shirt. You just have to tweak the bounce level on the cards to strike a nice lighting balance on the subject. I also often use brown shipping paper from below in front to eliminate the green without over lighting from white.
Mark
Mark D'Agostino
http://www.synergeticproductions.com
