Cameras changed huge when Red hit the market; effectively, they renamed 4K. Whereas it meant 4,000 lines of each R, G, & B, Red made it 4k across the top, with a CMOS. It caused a lot of discussion.
As a marketing piece designed to get viewers, the trailer ought to establish some general categories: who is the main character? Genre (example: is the movie horror or romantic comedy?) What does the main character need?
It’s a place to start. The trailer should not be less than that, although of course there is room to add.