I like the pattern you've set up with the people on the different floors of the building. I spent a lot of time looking at the different people in the image, and noticing what they were doing. I'm wondering if it might have been better if you had taken it a step further to the right. The odd angle on the left doesn't really add anything to the image for me.
I like the upwards POV. I find myself wanting a bit more space at right (a number of the people here are looking in that direction), and less space, or context, at left, since it doesn't seem to ad much to the story. I like how there's a bunch of other people in this photo also making pictures.
I made my screen smaller so I could get the full effect of the wide angle and it's very impressive - a real sense of looking up, I felt like I was there - except I see in color (grin) It's also a nice study of human behaviors when they don't know they are being observed - nicely done in every way.