[Alex]

Well, that would be one of my questions, how does she even know what another cat is and smells like to hate it and be jealous (and she isn't jealous of other things). Plus jealousy (I don't really anthropomorphize animals so I also don't really think it would be anything similar to what we'd call jealousy) wouldn't explain it all since she's woken me up in the middle of the night yowling at the window and when I looked it was because of a cat sitting on a balcony in the next building over.

Mostly I'm just curious that I apparently can't wash off or cover whatever smell it is that she's reacting to.

We did have a cat when I was a kid that reacted badly to a new cat in the house (and it was specific to the cat we had others already). Shortly after the new cat arrived she started peeing in the stove burners. Swear to god. Now, I in no way believe the cat understood the chain of events that would result but let me tell you that boiling off cat piss results in an extremely unpleasant experience. And it is really hard to get in the habit of checking the burners for pee before turning them on. When we passed the new cat on to someone else she stopped.