intertextuality: the interrelationship between texts, especially works of literature; the way that similar or related texts influence, reflect, or differ from each other
obligatory intertextuality: when the writer deliberately creates a comparison or association between texts.
optional intertextuality: it is possible to find a connection to multiple texts of a single phrase, or no connection at all.
accidental intertextuality: when readers often connect a text with another text, cultural practice, or personal experience, without there being any tangible anchor point within the original text.
Here Is a scene from Monster's Inc. where Boo is handing Sully a toy that happens to be of Nemo from Finding Nemo (both Pixar movies).
Here is a Simpson's parody of Van Gogh's "Scream" painting.
Here is a parody of Grant Wood's painting "American Gothic" with Minions from Despicable Me in place of the infamous farmer and wife.