Hmm, this is an odd one - there are images I rate higher in this free study but none of them I wish to favourite (which I have done with this), there's just something about the image that makes me want to stare at it, perhaps a sense that there is something truly spectacular happening just off of camera and staring long enough will reveal what that is.
Or perhaps it's something more subtle in the composition that makes this so appealing to me such as the movement leading out of frame both left and right: the man arching his back to the right of frame, the pillar in the middle leaning slightly to the right, the beams of light on the back wall moving rightward across the frame, one directing focus towards and hitting the man's face, and the left hand sign giving rightward movement with how it moves in to the centre of the frame. All countered by the left-leaning reflections, the sign gesturing to the left, and and man's gaze leading to the left out of frame.
Whatever the reason, it's a great photo. My only complaint is that the man being very slightly soft (or out of focus) is driving me slightly mad =). 8