Most of the characters at the old people's home are named for Batman villains who've been incarcerated at Arkham Asylum- Oswald (Cobblepot, aka Penguin), Harley (Quinn), Jervis (Tetch, aka The Mad Hatter), Pamela (Isley, aka Poison Ivy), and so on.
In the scene where Shawn, Gus, and Henry are investigating Oswald's living quarters, Shawn mentions knowing that the date circled on the calendar is the day of the Santa Barbara marathon because it coincides with actor Val Kilmer's birthday. The date on the calendar is December 31st, which is indeed Kilmer's birthday.
Shawn claims that Henry (charading as Talmadge McGulager) is 72, to which Pamela says she thinks he could pass as 59-60. At the time the episode aired, Corbin Bernsen, who plays Henry, was 53 years old.
Spot the Pineapple: the lamps in Oswald Chester's room have pineapple bases/stands.
The Old and the Restless is a play on the term The Young and the Restless (1973). Corbin Bernsen's mother 'Jeanne Cooper' plays "Katherine Chancellor" on the soap, and Corbin himself also had a brief role on the soap as Father Todd Williams. Joan McMurtrey guested on 'The Young and the Restless'