Wow, this is all getting very serious.
As far as I know the only time we ask passengers to shut window blinds is on a night flight when it is going to get light very early/half way through the flight as it will help passengers rest. I have been on other airlines who like passengers to pull them down on a day flight and then turn off the lights in the hope passengers will sleep!! Something I found very annoying as I had slept very well the night before my 9am check-in.