This image is a great candidate for simply enlarging the canvas, and giving him more room to look into. It would be a fairly easy edit to perform. it could also be cropped more tightly at the top, eliminating the 'unicorn' John mentioned, and also cropped a little bit off the bottom and the right hand side, which would direct his line of gaze just about right to the upper left hand corner, and I think that would give a slightly different feel to it, yet would still maintain the integrity of the moment.