How did you guess?
Thank you for your very complete and detailed answer.
Regarding the "chatting": I sometimes have the impression that the conversations they are having do distract them from doing their job. Maybe just an impression.
Another thing: I often see passengers baggage getting searched in public (on the tables on the left side when exiting). I think it's awkward to say the least. Even if I had done nothing wrong, I wouldn't feel at ease if it happened to me. I don't see this at other airports, maybe the lack of space at BRU is also responsible for this procedure?