That would serve the same purpose without and extra light, I think they’re into something

I think a secondary light that blinks quickly would be a good signal of emergency braking. Like some aftermarket motorcycle taillights that start with a blinking pattern before they stay on, but reverse the order.

So, standard brake light comes on at the standard time, at the first touch of the brake. For stronger braking, the second light comes on. For emergency braking, the standard brake light stays lit while the second light begins blinking frantically.

Edit for consistency

A few minutes of close-up. Otherwise, medium to far shots, shots where the camera is moving enough that a few blemishes in the robot won’t show up, or the focus is on another character in the shot.

Design for movies only have to look good for a few minutes of close-up, and there are many tricks for making them look better in those few minutes.

Shudders* Yeah, humanoid robots that can do advanced human style fighting pale in comparison.