When Ann brings her laptop to the hearing (to play Leslie's video of her and Ben), the laptop case she is using is the one Mark gave her years ago. This is one of only a very few references to Mark after he left the government.
The portrait on the wall of the Pawnee hearing room of the man whose face was scarred by an explosion is actually a retouched 1859 self-portrait of Jean-Auguste-Dominique Ingres, a French painter (1780 - 1867).
The song playing in the background of the video Leslie sent to Ann is the same song played when Lil Sebastian's owners and friends walk on the stage in "Lil Sebastian".
Leslie mentions having a picture of Bella Abzug on her desk. A picture of Abzug is also visible on the wall of her house in Leslie's House (2010).