Easter Egg: There is a drawing of The Red Faced Demon from the Insidious movies on a board in the Professor's office (roughly 59mins in).
The "Christmas Morning" kill film was the only one featured in Sinister 2 actually recorded on super 8 film. The others were all recorded on 16mm. "Christmas Morning" was created several years prior to the others, and was originally going to be included in the first Sinister film. It was left out for various reasons from the first film, mostly because including it would require extending the length of Sinister in general.
The rural farmhouse and cornfield setting was chosen because Sinister 2 is an homage to Stephen King's "Children of the Corn".
(at around 1h 19 mins) During the cornfield scene, the camera pans out to show the cornfield is in the shape of a skull using two dirt piles as eyes and the car as a tooth.