Quite fascinating to watch from the outside. I went looking on google to see if I could find the name of the program, or a youtube (it was that amazing a change in surroundings, not subtle at all), but no luck.
Reminds me of an early date with my (now) husband. We sat in the restaurant talking. All the people left. The restaurant closed. The waiters put chairs on tables and vaccuumed, etc. We didn’t notice. We were absolutely engrossed in our conversation. Eventually, staff told us it was time to go, and we were completely surprised. We had been there about 2 1/2 hours.
I suspect that the girl you mention who was on a date is not the usual female. Most women’s brains do not function that way. I suppose it’s some sort of hard-wired protection that has us checking out our surroundings and noticing what’s going on even as we are concentrating on something.