Don't worry about it. The problem now is it is so unnatural not to take pictures or film almost anywhere in the World- plenty of people would not even "see" the signs even staring right at them.
Plenty of, for example, twenty-something occasional travellers could not comprehend the concept of not being able to use a phone anywhere. Its just alien to some.
Much like the BA forum here where more and more threads have nothing to do with BA. It's just accepted.
Sounds like a wonderfully eager member of staff that worked to your advantage. Just imagine what it is like doing that job- fighting an uphill battle - and your interaction probably excited him somewhat.
In a crowded Arrivals area you've basically posted an interesting tip.