The Watching documentary primarily is a detailed film looking into the opening title sequences of thriller films and what makes them interesting/relevent to the audience and story.
It was said by Thomas Sutcliffe "Films need to seduce their audience into long term commitment. While there are many types of seduction, the temptation to go for instant arousal is alomost terrible." What Thomas means by this is that the opening of a thriller movie needs to indulge the audience into immediate curiosity. This is so the audience are immediately "pulled" into the film thus causing the audience to keep watching to find out more.