Yeah, while fatphobia is definitely a thing and fat people are definitely not more likely to be violent than anyone else and LW is definitely being an ass about how they wrote the letter - sheer size *is* an advantage in a physical fight, and I *am* going to be more intimated by somebody twice my weight than somebody half my weight, whether that extra weight is height or fat or muscle. And every large person I know (and every small person I know) is aware of this in their body-language interactions. So it's pretty disingenuous of Prudence to just outright deny that a large person deliberately using aggressive body language couldn't possibly result in LW feeling physically intimidated. They probably did feel physically intimidated, and the size difference was probably a factor, and the person they were interacting with was probably using that deliberately. How to deal with the fact that size *does* change the intimidation factor, and how to handle that in a just way, is something that is an issue for large people of all types and I don't have an answer for.

It's also not particularly relevant to the question, and a better answer would have been to just leave it that the person screaming at you should not have done that and then moved on.