When working on 3D you have to be quite organised to avoid losing yourself on little tasks. Details are meaningfull just if they add identity to the scene. What if I had a dog instead of a cat on the scene? Well it could be sleeping, but they tend to be more active so maybe having it on a calm scenario, could not contribute to the whole meaning. (Pst: im a dog person, I know how they get whe you move a little bit of your seat). These kind of things transform the feeling of the piece.