The poster on the door in Jake's childhood room says hot rod on it. Andy Samberg starred in the movie Hot Rod (2007).
Captain Holt asks Scully if he has any experience with puzzles. Scully replies, "Yes, I've never solved one." Joel McKinnon Miller (Scully) frequently posts pictures of solved jigsaw puzzles to his Twitter and Instagram.
Captain Holt's "Escape the Room" challenge takes place in a space made to look like a 1950s-era fallout shelter. Without any apparent reason or explanation, the American flag on the wall is the 45-star version, which was introduced in 1896 when Utah became a state. It was the official flag until 1908, after Oklahoma became a state when Theodore Roosevelt was president.
The poster on the wall in Jake's childhood room was previously featured in USPIS (2014) on a suspect's wall. It is for the band Saves the Day. This was from a show at the Troubadour in Los Angeles, on their 2006 tour with openers Circa Survive, Moneen, and Pistolita. It was designed by renowned poster artists Dkng Studios early on in their career.
Katey Sagal, Bradley Whitford, and Andy Samberg, who play parents and child, were all on genealogy shows trying to find info on their families. Andy Samberg went on Finding Your Roots with Henry Louis Gates, Jr. (2012) and was able to find his mom's birth parent. Katey Sagal went on Who Do You Think You Are? (2010) and was able to trace her mother's German Amish ancestors. Bradley Whitford also went on Who Do You Think You Are and found out about his family's involvement in the Civil War.