This analysis of a scene from Lights Out talks about the importance of editing and camera direction to make a scene scary, and compares the short film version of Lights Out to the same scene in the release, which is included in the film’s trailer. Here is the analysis by Now You See It, just watch the first 2 minutes:
@SwagThuf4Lyfe prefers the short film version. I liked his detailed analysis, but I thought he overlooked the importance of the actress in the scene. The movie version has clearer lighting on her closeup, so her reaction shots can do more of the work in the set-up.
At the jump scare, the monster is facing the victim, still in shadow, with lit-up eyes – this is a more threatening pose than the partially-visible figure in the short film version with its back turned. I agree the monster’s point of view can be scary, but if you are going for a trailer-paced scare, there are advantages to focusing the audience on the point of view of the scare-ee.