So which do you think it is?
It is an artifact added to the photo either as part of the processing, to cover up something else (take a glance at Washington DC on maps.google.com, especially federal buildings), or just put there to entertain us. It can not be an object that was originally part of the image because of the reflective highlights on the object vs the shadows from the trees.
So which do you think it is?
Well, now that I've
found a second one diagonally to the northwest... I donno. Fuzzing out something might make sense over in one area - but in this second area it doesn't. Unless these are markings for Jeb's drinking buddies, I'd have to suppose that the only possible logical explanation would be line up markers but that is hard for me to swallow.
Perhaps you can find a few more of these in and around West Palm Beach and the larger pattern might make more sense. All I know is that while the second object lines up better with the shadows, it is still not good enough to support the idea that these objects existed in their locations when the images were taken.
Artifacts added after the fact.. I'll be really annoyed if it turns out that it was someone's child who was playing with the raindrop tool on Photoshop.