The difference is in the intent. A security camera films a place and doesn't focus on individuals. If the camera were to run software that would autofocus on a person, that would make them a subject, there would need to be consent.

You'll find a helpful diagram (though incomplete) on this page https://fr.wikipedia.org/wiki/Droit_%C3%A0_l%27image (French), and there's of course (as anything legal, it's a rabbit hole) more specific laws concerning security camera.

But surely the only point of security cameras is to montior people? Your not watching to make sure the safe didn't grow legs and walk off.