beta
Some people really need to take metaphor for what it is, if you replacing the person with the visual of a cat is aimed to make us uncomfortable especially when it is revealed that the girlfriend is not turned into an actual cat but has become a pet in their relationship. This distorted imagination might also be because everything we saw in the first 3/4th of the story was from the cat girlfriend's perspective which is distorted to the point that she could not differentiate between her imagination and reality until the moment before her death.
Even the scene where the girlfriend's mother keeps banging at their door shouting that she cannot care for her as if she's an infant which again is aimed at the readers to doubt what they are seeing. She was not 'hiding the cat' instead she was running away from the truth that she could no longer tolerate her behaviour.
Also, the story does not explicitly give any timeline but the girlfriend moving in with her new girlfriend in the last scene does give a hint that atleast a couple of months have passed (which means our protagonist is admitted into the mental institution for months and has lost her touch with reality).
I hope we get more from this author and more such distorted perspectives.