Stuart it's a nice pose, but the sharpness just isn't there. Is this a large crop?
I think you had too slow SS (1/60) for the focal length AND the high megapixel sensor (the D800 series needs way more SS than normal cameras to negate the effects of camera shake).
It also looks like your focus was not spot on between the eyes? But that's hard to quantify given the shutter speed effect.
The whites on the ears look overexposed too.