The early scenes of Jurassic Park - Stephen Spielberg (1993) are key to getting a hint about what the movie is about if you had no idea what it was. It uses many cinematic devices to help the audience get an understanding of what is going on and what could possibly happen later in the movie.
The first things you see when the movie starts is the Universal Studios logo. This is accompanied with music which sounds like it would belong in the jungles/rain forests. This could denote that the movie doesn't take place in familiar surroundings such as a busy town and more likely to take place in isolated jungles. After a while the rainforest sounds and Universal Studios logo fades out and is replaced with a single low note which is raised in volume and pitch before stopping suddenly with a single drum beat when the titles pop up. This repeats three or four times which links to the idea that dinosaurs are about. The note's use of volume and pitch can denote the idea of the dinosaurs walking around. By this time the audience will be waiting eagerly for something or anything to happen, and by doing this with the titles Spielberg has managed to keep the audience on the edge of their seats with excitement.
The first actual shots of the movie consist of forest foliage and rustling behind the trees. After the audience being teased by the duration of the titles the majority of them would be expecting something huge, such as a dinosaur to be the cause of the rustling and movement behind the trees. What's behind the foliage isn't revealed until a couple minutes into the film to once again increase the tension and excitement of the audience and movie.
The shot after seeing the movement behind the trees shows several actors stood watching whatever is behind the trees. The costumes the actors are wearing also suggest that they're working on whatever is behind...