This is a scan of a dusty print. Though I took the picture from my roof, this message was primarily over Manhattan. The building in the lower left corner is the apartment building at 417 Main. In the lower right corner, you can the Bank of America building at 210 Main St.
I had to use a fisheye lens to get the whole message in. I have no idea what the message was about, but I can make out the word "SALE" next to what looks like an 800 number in the lower left quadrant.
If the sun had been just outside the circle, the image might have looked like a diamond ring.
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