Nice movie!
It really emphasizes how the stall initiates from the trailing edge and runs quickly towards the leading edge. Additionally it can be slightly noticed that the wing root is stalling before the wing tip, but maybe this is a bit of an illusion.
To be honest, although I know about the tuft on the WW glider, I could never really focus on it when practicing stalls...:-)
Eyal
(sorry for the English, I do not have a Hebrew keyboard near me...

)