Thinking of the flower market photo posted recently, I worked on this catch at the local farmer's market. Maybe faces aren't needed to create a feeling.
This image definitely tells a story, without faces, so I guess you are right, it does create a feeling.. The question I would ask is if this image would tell a stronger story with faces, I think probably yes if the faces compliment the story told with the hands..... Are faces needed always needed, I think no IMHO, but they can help show the emotion of the moment, which may compliment the image.
Hazel, nearly but not quite. In this case because of your low angle you could have included the child's face after that arm got out of the way and added to the interest of the shot. In my flower market shot it couldn't be done because I was holding the camera about 8' or so directly overhead. So you and Don are both right depending on the situation.