That is detail to the model, not the animation.
No wonder it took almost 15 years
Disney has invested a ton in research and pipeline work to allow complex hair/fur animation. This is most likely animated, especially considering that you can see the fuzz hairs coming off the shirt.
It's literally a detail in a movie though
yup. Brave may not be the most interesting movie, but the work they did on animating hair in that film deserves its own oscar.