When Warren's daughter, Jeannie, fixes him a sandwich for lunch, while on camera, Warren is seen taking two bites from the sandwich. The sandwich is shown with a bite missing and then appears later to have been uneaten.
In the scene where Warren Schmidt falls asleep in the bath, his posture is exactly like Marat in the painting 'Death of Marat', by J.L. David. You can take a look at the original at http://www.artchive.com/artchive/D/david/marat.jpg.html