i agree that he looks like a big pussycat, but i rather _like_ that about this image... it's a photo of a big goof, not a fierc preditor, and i fund that funny... heck, he almost looks like he's smiling...
as for what i'd change, i might try a slightly different crop (though, not having seen the full frame, not sure what you had to work with...) even something more square would feel more intentional, maybe...
also, i'd try to clone out the brown weed/plant in the center of the left side...
A beautiful vivid shot, with outstanding clarity, and a nicely captured pose. The catchlights in the animal's eyes are an absolutely wonderful addition, and really make this photograph for me. The tight composition with its portrait orientation is not my favourite. Though certainly beyond your control, the position of the animal ulitmately harms the overall composition in my opinion; when I think of a tiger, I think of a tense wall of muscle ready to pounce, a ferocious killer, an animal that defines action. This guy's just a big orange pussycat. :) Nothing wrong with that, certainly, but maybe my expectations have not been met, though that isn't necessarily your job. Technically, though, in general this is of course a great photograph, well captured.
I REALLY like this shot. :) The composition is excellent and I think the colors really pop. Good use of a subtle border, though I probably would have cropped out the brown plant that is visible in the left side of the frame. Very good use of DOF as well. Great capture!