When Bob walks in the door with his dog he takes a towel and dries the dog off . After he is done he hangs the towel on a hat rack . Then in the scene where Bob's wife , Elizabeth , walks in the door , you will see the towel dissappear and reappear several times on the rack .
I noticed this too. And I think it's a scene somewhere near that one, that i noticed that the dog's water bowl is there in one shot and not in another right after it. I think it's where he was trying to get him to eat rice.