I was thinking she was rude and/or very OCD (in the literal sense, I have it, and it looks like germophobia, but it's really just about touching things others have touched, germs or no), until this:
She directed every person who came up to her station to another station.
The fact she was directing people away, coupled with the cleaning fervor, indicates to me that maybe she was cleaning up after someone or something *before* you. Maybe someone put a kid in a messy diaper on the belt, or someone threw up on it, or someone *had* sneezed on it, and she was trying to get it to where she felt like it was properly clean.
If not, then she was rude, or has some rather bad OCD and probably needs to find a job where she doesn't have to handle strangers' things.