On Route 4, while the Nim event is active, when standing on tile in a down right diagonal position from her character, she will rapidly look up and left
the same goes with the upper part too, when Nim is positioned like this and you're standing in a up right diagonal tile from her, the same thing will happen, except she looks down and left
I assume she is normally supposed to walk up and down seeing as whenever I got from up to down she walks to the other side but I don't think the rapid looking is supposed to happen.