It is imperative then to cut the first look very meticulously. Though the rules say that 1st look should give out the main characters, the basic plot and the premise of the film; I feel over the years, filmmakers have consistently broken the rules and have used innovative approach to present the 1st look to the audiences.
Idea is to grab the eyeballs of the audiences with the 1st look itself! In this age, when the attention span is really very short, it is beyond doubt that you have to capture audiences anyhow and the first look goes a long way in doing that!