The repetition side of his definition is that in films and TV etc. for certain genres, the same props, settings, acting styles for example help people to recognise the genre very quickly. As an example, horror movies will always include an eerie setting, jump scares, a group of culturally and intellectually different individuals alongside tense music throughout. People would instantly be able to recognise a horror film because the conventions are clear and would know what to expect from possible past experiences.
The difference side of it however, is when a production company adds new and different things to make it seem more interesting and not like a clone of all the others.