This is an interesting lesson for those trying to understand the tradeoffs of shutter speeds, especially in surveillance where slow shutter / sens up is so common.

Here's a typical stoic image from the 1800s:

The impression given is that people from the 1800s were very stern / Victorian.

However, another technical explanation is often offered that, because those cameras required a 3 second (or possibly longer) exposure, people had to stand still, motivating them to adapt this strict / stoic posture, lest they have serious ghosting from moving their heads, mouth, etc. while the picture was being taken.

By contrast: