But the thing we noticed most was that Sheriff never reacted to these expressions of disgust by GirlKitty. They were usually delivered right in Sheriff's face. But her body didn't move at all. We knew because the bell didn't tinkle. We talked about this as well, relating it to our own experiences.
Eye contact is crucial to cat communication, but it's very important to people as well.
GirlKitty seemed very puzzled that she was getting no reaction from her fierce glare and hiss. We have both known people who were very uncomfortable talking to us. It has often seemed to us that part of the discomfort comes from lack of eye contact and uncertainty on the sighted person's part that we can detect they are talking to us. In Sheriff's case, of course, it just may be that Sheriff has better manners than GirlKitty. Anyway, she's found her own form of revenge.