Why is it important to consider a specific film's purpose(s) when using film theory?

Film theory or cinema studies is an academic discipline that aims to explore the essence of the cinema and provides conceptual frameworks for understanding film's relationship to reality, the other arts, individual viewers, and society at large. Knowing a film's purpose will let you know how well the film has captured these aspects.

Riffin tells a story about photographing elephants in a wildlife sanctuary in africa. he says that the photographer brought back more than just an amazing story.