When Jim is looking for Dwight's farm on the internet, Google Maps has a picture of him and Mose seesawing. In s06e16 Manager and Salesman (2010) Ryan asks Dwight "Did you see Saw (2004)?" and Dwight says "Of course I seesaw, Mose and I seesaw all the time".
Towards the end of the garden party, Pam, seeing Dwight and his catering employees with torches doing sort of tribal ritual, asks Jim "what are they doing?" Jim says "closing ceremonies." "Nice touch," Pam says. Closing ceremonies are important to Pam and Jim and the conversation in this episode closely mirrors an interaction they had in Season 2, Episode 3 "Office Olympics."