In Death to Smoochy, Sheldon sits down at his desk and smells his "own little patch of wheat-grass" given to him as a present by Burke. Tommy and her crew talk to Sheldon a bit, and then leave. As Tommy's crew is leaving, there is an above camera view of the office when Sheldon's phone rings. You can clearly see Sheldon reach for his phone, and also the patch of wheat grass sitting on his desk. Then, the camera changes to a closer straight-on view of Sheldon, but now the wheat grass is on the sill behind him, where it will remain for the rest of the scene. At no point in time could the patch of grass been moved. No time elapsed in between as evidenced by the scene for Sheldon reaching for the phone (with the grass still on desk) and him answering the phone with his first words (with the grass behind him).