In the film "American Psycho," Patrick Bateman gets tense when Luis Carruthers shows him his business card because it is of superior quality compared to his own. The scene in question highlights the theme of competition, envy, and obsession with status and material possessions, which are prevalent throughout the movie.
Patrick Bateman, the protagonist, is a wealthy and successful investment banker, but he is also a psychopathic narcissist. He is obsessed with appearances, perfection, and being perceived as the best among his peers. The business card scene is a perfect example of this obsession.
When Luis shows his business card, Patrick realizes that Luis's card is more elegant, tasteful, and sophisticated than his own. This discovery threatens Patrick's fragile ego and challenges his self-perception of being superior to everyone around him.
In the movie, Patrick is shown to have an extreme attachment to his own business card, seeing it as an extension of his identity and self-worth. He spends considerable time and effort perfecting it to demonstrate his status and uniqueness. However, when confronted with Luis's card, which he perceives as better, he becomes extremely envious and feels inferior.
The tension in the scene arises from Patrick's internal struggle to maintain his image of being the best while facing a challenge to his self-importance. This moment reflects the shallowness and materialistic nature of Patrick's character and serves as a commentary on the empty pursuits of wealth, status, and societal validation present in the world of the film.