Also late getting started, but the major Hitchcockian things that stood out to me in this clip are: 1) The high shot POV fro over the stage and 2) the scenes when action is taking place in "background" while the foreground is taken up by inanimate objects. (Unfortunately I've never seen Dial M in 3D, but even in a flat print, Oh my, all those table lamps.) Of course great comical and semi-comical CU and Mid reaction shots.Yes, yes, yes, the spiral staircase. But the shot that I found mesmerizing was the double refection in the glass at the box office as the girl is looking for her letter of introduction,