Here's my take on investors. They want an idea that their money is in capable hands. If you can make a stunning trailer with a handful of shots, and I'm convinced that an artist can do that deftly and beautifully, then go ahead and make your trailer.
Investors are not expecting the choicest shots from a film that has not been made yet. They are expecting to be blown away by your skills at capturing the essence of your film. Are they expecting that shot of the Grand Canyon that conveys man's isolation from himself? Of course not. But maybe that shot of your protagonist alone in his backyard captures the same feeling of isolation and loss, not that that's the kind of film you want to make. But you get the picture.
