An actor is shown posing in front of a mirror, but off to the side so that the camera captures his reflection. Given the slender width of the mirror, the actor is seeing only the camera in the reflection, and cannot actually see himself.
One of the Paramore posters in Vivian's room features a logo with three slashes for the E in "Paramore", which the band didn't start using until 2013. The film takes place in 2008.
Chris' friend, Fahad, tells a joke to entertain two girls. Chris points out that the joke is originally by Dave Chappelle. Notably, the joke is from Chappelle's TV special Nel cuore del Texas: Dave Chapelle dal vivo all'Austin City Limts (2017), which was released in 2017. However, the film is set in 2008.
During a scene at an arcade, a "Down the Clown" arcade machine is shown. This machine was not produced until 2017, while the movie takes place in 2008.