I'm also intrigued by the many messages with constructive advice about making the photo less "ambiguous" as to the intentions of the man in the photo. It's good food for thought, and a good reminder to me that a person looking at the photo has *none* of the "context" that the photographer has when he/she is on the scene.
For me, actually being there, it was *obvious* that what was happening was a very nice act of generosity ... and I'm not sure if I could successfully turn off that "context knowledge" when I look at the image on my computer. Maybe really good photographers can do this; in my case, it would be a lot easier to simply get the kind of feedback that has been offered by everyone on this thread.
(All of that is separate from the may pieces of good advice about tilting, cropping, sharpening, etc. That photo was taken 4+ years ago, and I've gotten a little better since then ... but still have much improvement to make.)
As for the suggestion that perhaps I should have waited around to see if a better variation on this scene presented itself ... well, in general, that's very good advice for me: I tend to see a scene, take the shot, and move on, much too quickly. But in this case, I remember staying in the same position in case *other* interesting people came along. And I can tell you that once this guy dropped the money in the woman's cup, he moved off somewhere else and never returned.
But it is indeed quite possible that if I had taken the photo a split-second earlier or later, it would have been much better....
Or maybe not. Maybe this photo was doomed to be mediocre -- for all the reasons suggested by people in this thread. But in any case, I've learned a lot, and I thank everyone for offering their comments and suggestions.
Ed