Visible crew/equipment: In the beginning, Kristi takes Hunter out of his highchair, then it falls over. When Kristi went to go pick it back up, she stepped over the string used to tip it.
Paranormal Activity 2 (2010)
1 visible crew/equipment mistake
Directed by: Tod Williams
Starring: Katie Featherston, Molly Ephraim, Micah Sloat, Brian Boland, David Bierend
Continuity mistake: When Kristi sits down to have her coffee and read her magazine, the coffee cup is perfectly in place before the cabinet doors burst open and she runs away. When she comes back and closes everything, her yellow coffee mug is gone.
Trivia: Notably, the previews for this film (and several other sequels in the series) contained footage not seen in the finished movie. The previews were often made primarily of footage from alternate and deleted scenes. The producers and directors hinted that this was done to help keep the story secret, despite being a bit shady on their part.
More questions & answers from Paranormal Activity 2
Chosen answer: It's the demon.
Manky