Before Chrissie reaches the top of the slope there is a cut to a low angle shot of the sand dune. A dilapidated fence curls along its spine and the background sky is full of glowering clouds. In contrast to the warm golden light of the campfire scene, the image is dominated by shades of grey and charcoal. The girl's silhouette appears on the seaward side of the fence. She pauses briefly and looks back to make sure that the young man is still in pursuit. The outline of his figure can be seen at the far left of the screen several yards behind her. Strictly speaking this arrangement of the two figures at the beginning of the chase along the dune is an error of continuity. In the previous shot both characters ran up the same slope and should have emerged at the top together on the landward side.
Since the advent of video, identifying continuity errors has become the film buff's equivalent of trainspotting. One website lists two hundred and forty one continuity errors (or goofs) for Jaws - ranging from camera reflections and mismatched costumes to spelling mistakes and rearranged furniture. Given the nature of the filming process - and, in particular, the process of filming Jaws - it isn't surprising that the movie should contain so many little flaws - mistakes which are so insignificant that they can only be exposed by multiple viewings when combined with a degree of obsessive-compulsive behaviour.
In rearranging the positioning of the two characters at the top of the sand dune, Spielberg was prepared to forego literal continuity for a visual image that conveyed a sense of the girl's flirtatiousness. Her backward glance is a tease, as is the way she replies to the boy's two questions ("What's your name again?" and "Where are we going?") in an excited rising intonation. She wants him to pursue and ultimately catch her, and her later cry of "Come on in the water" betrays a slight sense of exasperation that he has not followed her.