Comma usage in short sentence

I think Clive mentioned something like (something to the effect?) that if we have a short sentence, a comma can (could?) be used to give emphasis. Does this definition of the word "film" from Naver.com (onine) dictionary fit that? A comma placed after the word "story" but before the conjunction "or" for emphasis here?

A film consists of moving pictures that have been recorded so that they can be shown at the cinema or on television. A film tells a story, or shows a real situation.[ mainly BRIT ]