Eudory Welty once said that 'Every feeling waits upon its gesture' Your sons hands clasped as they are could be a sign of self comfort of anticipation or excitement. Whatever the reason it is not without meaning and as we get older the meaning of clasped hands can become more complex and more strained or indeed for the very the same reasons your son's clasping his here. In 1931 Alfred Stieglitz shot Dorothy Norman, he would later write to her telling her that he believed he saw "Gods light in her face" Your sons face gently lit by the window light and and clasped hands could also suggest that of prey and revelation-Gods light in his face (i'm not religious by the way). Stieglitz was fascinated by hands and this shot reminds me of how hands have always been important to photographers, from Lange to Weston to Stieglitz. Of course he maybe just watching the TV, but it is symbolism and not narrative that photography relies upon.
