Ann shows the audience her boxes of things from her ex-boyfriends. She mentions Tom and Chris but excludes Mark Brendanawicz (Paul Schneider), he isn't even mentioned.
Ron is wearing his pirate costume he wears every year.
When Ann is showing off her "ex-boyfriend" boxes, the box with all of Tom's stuff includes the "Baller Time" pocket watch that Leslie gave Tom for Christmas in the previous season's episode Citizen Knope (2011).
During the tag sale, April (Aubrey Plaza) is seen holding one of the Marshmallow Shooters that she purchased in Jerry's Painting (2011).