I've posted these walking down the street shots before (here and here). Most I find are boring, and there is certainly nothing exceptional about this one. What I do like is that the subjects were ignoring the photographer, but the woman behind them is all smiles. Was the woman behind hoping her photo was taken? I imagine the photographer missed her since he was probably too busy handing his card to this mother and daughter (or sisters).
Click on image to see it larger.