After the gate was open and flight attendants were standing idly waiting for the signal for boarding, I (young man, well-dressed) politely asked a flight attendant if I could take a picture with her for the memory, and she refused on the basis that it weren't allowed by the airline.
I tried asking two other flight attendants (they had no idea that I'd asked another flight attendant before, so their response was not influenced by the fact that someone before them had already declined) and received similar answers and then gave up.
(The specific airline was Emirates)
So what is the reason that flight attendants are not allowed to take pictures with passengers?
Are there situations where they are allowed to appear in photographs? (I remember one time, also on an Emirates flight, that a flight attendant took a picture with a child because it was the child's birthday)