I imagine it's a mix of political pressure from Scotland doing it, the WHO changing their stance (funnily enough, due to political pressure), those who have been screaming for it to be done for a while being heavily publicised, them trying to convince the people they've scared in to come out now they need it for the sake of the economy and the attitude of 'we must do something, this is something, so we must do this'.We did our weekly big Tesco shop today instead of tomorrow to beat the masks. I didn't go around counting everyone, but mask wearers guestimate around 10-15%, which tallies with what others have said today. Saw 1 staff member inside the shop wearing a mask (plus the chap at the entrance with a face shield).
I think this is a very dangerous moment in the whole crisis, with a real potential for conflict between individuals. Trust in Government handling of the crisis has been falling, especially since the Cummings debacle and they haven't done anywhere near enough to justify why mask wearing is needed now, when it wasn't when the virus was rampant in March/April.
The Chief Scientific Advisor and the Deputy Chief Medical Officer (a world authority on influenza) were adamant in March masks made no difference. Did they really get that so badly wrong, or is Hancock making it up as he goes along? Do you need half an hour to work that out?
I don't believe there's any science behind it, it's entirely political and psychological (trying to make people feel safe), whether it works will be anyone's guess, but I think footfall will decrease quite sharply.