Shawn mentions that one of the portraits in the lodge lobby looks like "Chuck from Wonder Years." The portrait is of writer Andy Berman, who did in fact play Chuck on the show The Wonder Years (1988)
Hanging in the lodge lobby are portraits of past members. Most of these portraits are of crew members from the show, including creator Steve Franks and writer Andy Berman.
The photo of the woman on Holmstrom's desk is in fact real life mother of actor Corbin Bernson, the late Jeanne Cooper.
When Shawn and Gus speak to Mr. Parker's secretary, Gus uses a false name for Shawn, calling him "William Zane". This is clearly a nod to actor "Billy Zane", who is mentioned numerous times throughout the series.