Good points. Those things do seem to argue against my flight attendant idea.
Of course the head coverings could be something that they would normally wear only when out in the sun, and remove when in the airplane.
It’s also possible that covering their head in that manner was a religious or social expectation having nothing to do with indoors versus outdoors.
Something else - the bench they’re on is reminiscent of what people sit on in a bus terminal or train station, and the surroundings in general give me the impression of that type of facility. It could be one of those two things, but it’s also possible that it’s a small airport in a poorer country in an earlier time.
But I’m less and less certain of my “flight attendant” answer.
Possibly Philippino or Indonesian muslim. It would explain the head coverings, no? It doesn’t explain the pants, of course, but that’s my answer and I’m sticking to it.