Disclaimer: Woefully ignorant here in cognitive sciences but the mirror test has always seemed ambiguous to me. How do they determine that the animal is not j

Disclaimer: Woefully ignorant here in cognitive sciences but the mirror test has always seemed ambiguous to me. How do they determine that the animal is not just...well apathetic about seeing themselves in a mirror? For worthless anecdotal example my dog (and per that link dogs don't pass this test at least officially) when she was a puppy did react to the mirror but now never does as an adult. Why does that not just mean she's...well not particularly vain? Edit: Just saw the extensive section in your wiki link on "false-negatives"...which is my entire post so...it's a thing after all.