I think this may be more of a safety measure, than a security measure. Taken from
here:
Quote:
Shades up on takeoff and landing. “Why?” a reader asked. “Sometimes I think the flight attendants are just on a power trip. Here I am, pupils scorched by the sunlight, desperate to get some shut-eye, and I have a flight attendant yelling at me to put the shade up.” Answer: In an emergency you will need to have the shades up so you can see what is happening outside the aircraft.
|
If something bad is going to happen on an airplane, it's probably going to happen on takeoff or landing, so it makes sense to be aware of the environment outside.