I'd reckon the closest thing we have to an official, network-wide policy on duplicates is found in the 2010 blog post, "Dr. Strangedupe: Or, How I Learned to Stop Worrying And Love Duplication":
Here are my official guidelines on question duplication:
Having one "perfect" form of a question that contains every possible answer to every slight variation of that question is a myth at best and actively harmful at worst.
Having dozens and dozens of variations of the same question is clearly bad.
What we want is on the order of 4 or 5 similar-but-not-quite-the-same duplicates to cover all possible search terms and common permutations of the question. It is also OK for these duplicates to have their own answers so people who find them don't have to click yet again to get to a good answer.
The idea of a massive canonical Topic FAQ is persistently alluring; instead of having 50 questions about a "sorting hat", you could just have one question with a few dozen huge answers! However, this quickly becomes impractical:
- Massively broad questions don't rank as well in search results as specific, focused questions.
- Folks with specific, focused questions tend to not read massively broad FAQs even if they do find them.
- Finding specific information among multiple answers to massively broad FAQs is troublesome.
- Remembering which information is even contained in these tomes is difficult; eventually, folks just start to assume that they contain everything and close new questions without worrying whether they're actually answered or not... This chokes out new information.
What does this have to do with your question? Well, normally the presence of identical answers is a pretty good indication that the questions themselves are the same (unless the answer itself is something trivial like the name of a character). But this doesn't hold if a question has managed to attract a lot of different answers - so you end up in situations like this where various answers might be applied to completely different questions even though most of the answers are inapplicable. Frankly, this is a wee bit silly, and smells more of folks being bored with the topic than anything else.
To avoid looking silly then, I would strongly recommend using answers as more of a litmus test than as a policy: if you're already pretty sure the questions are duplicates, testing the answers of one against the other can easily confirm your suspicions. But don't close completely irrelevant questions as duplicates of one another simply because there's an animated gif that happens to apply to both...