Events within the trailer?

1. Upside down NY city/ Ordinary day.

Questions the event raises? - Is there a reason for this to be upside down ? is this the start of a day that is going to be different for some? why does it say on any ordinary day but the picture is the wrong way up?

2.Cast heading into work.

Questions this event raises?
Are these the cast that the film is going to be based around?
Is this where the Devil strikes?
Is one of these actors the main focus of the film?

3.The opening of the elevator in slow motion.

Questions this event raises?
Why is this scene shot in slow motion?
Is this the lift where the movie takes place?
is the older women looking at him first because she knows something is going to happen?
why do they both seem cautious to get into the lift?

4.Cast in the lift through the security cameras screen.

Questions this event raises?
Why did the director use this editing technique for this scene?
What is it the woman is showing the other cast?
Is someone in the lift responsible for what happened to the women?

5.Reflection in the mirror/window

Who is this person in the mask?
Why is it there?
Is it one of the cast members from the lift?
Is it targeting the security man in particular?
Is this the devil?
what happens after this end shot?

These 5 events i believe are the key elements/scenes throughout the trailer as they tell the story without even watching the actual trailer. All the questions that will arise in these scenes would make the viewer want to keep watching to find out more and at the end of the trailer they will have been most likely persuaded and enticed to go and view the film in the cinema.