I have a genuine affection for these little (what I assume are some kind of) industrial fans.
It's entirely possible that their varying sizes and vaguely anthropomorphic shape make me think of a group of friendly, roof-dwelling robots.
Here they are in a larger setting:
I was struck by the way the cranes seem to be emerging from the fog, as if coming together to form a crane army. The streetlamp is clearly the leader. I wonder what he's promised them...