I think some people are more visual or aware of surroundings more in general than I am. I very likely would not notice if something was taken off my wall at home, let alone at the therapist's.
I notice whether I can see the clock on the table or not. If not - I take off my watch and put it on my knee. I never, ever touch any of the therapist's stuff. I dislike it when I have to move a pillow on the couch. I do wish the one had chairs instead of her awful awful sofa.

I think that furniture changes have more of an effect on me than room changes, for the last few weeks that I saw my most recent Therapist the couch was in the process of being fixed so I instead sat in a chair, but it also meant that I was seated closer to her for the last few sessions which I thought made the sessions a little more intimate.