I really liked this when I saw it. It's down to multiple factors... The fact that the angle of shadows from other buildings line up with this one - down in the lower left hand corner, and on the sign in the lower right hand corner. A lovely synchronicity there. The lovely blue sky, which peeks through both the trees and a few holes in the building itself - yet more synchronicity. And then that's all contradicted by the way that the staircase (if that's what it is) goes against all the other angles of the building. As if the building itself is railing against the synchronicities that caught me so.
After some time trying to think about what it was that kept drawing me back to this photograph, I realised it was all about those angles, and the way they played with everything else going on right at that point in time.
And I'm just a sucker for angles.
Incidentally, this was taken on the same day - and a few minutes before - my photograph of Senate House. It seems that was a pretty productive day...