Many people take pictures of the skyline reflecting in Cloud Gate (aka The Bean) in Millenium Park.
This weekend I stumbled upon another source for skyline reflections.
I know I've passed by this reflecting ball at the far east end of Pioneer Court a number of times but never noticed that it reflected the buildings around it. There is a possibility that the sun's angle at this time of year turns it into a mirror. Perhaps you don't get any reflections when the sun is higher in the sky during Spring, Summer, and Fall.