It appears that some of the satellite images supplied by Digital Globe to Google for their maps of Chicago are actually taken from different angles. When stitched together, this leads to a sort of cubist view of the skyline. In fact, the images are not stitched together along a straight line. I’ve included one of the most prominent examples.
Here is the original scene as displayed by Google earth:
Here is the scene with an imaginary line showing the apparent stitch line: