I don't think pixelation is exactly what your looking for.. there isn't even any grain to the photo your composting with. Although there is a little dust and maybe a scratch. I might try to add a white dust spot hear or there on the models..

It looks really good, the only real detractor from it is that the plug on the back of the neck and the closest model is to sharp in focus. There more in focus than the human, so that makes them look like there popping off and are closer to you than the human is..