I think this is one of those pictures where we are just looking the wrong way. A slight tilt to the the photo. However, the moment you captures is very, very well done. Emotion is a key element to photography and you have it here. While not a top 10 photo it is still underrated in my opinion.
Nice photo, but I wish we could see more of the man's face. On the post-processing side, this probably needs to be rotated slightly clockwise. It also appears to be over-sharpened. Notice the halos around the man and where the dog's back meets the sign.
I took a people photography class some years ago, and the first lesson was geared toward awkward places to chop the human body. Cutting the body off at major joints almost always looks accidental rather than one's compositional intent. Chopping him off at the knees, as well as cramming them tightly into the frame makes this seem like more of a shot-from-the-hip snapshot than a thought-out, composed image.
The composition here is alittle tight for my taste, and the photo has a rather washed out appearance. There is something about the texture (or perhaps lack of) of the dog's coat and the boy's hand that bothers me.