Use your mouse to move the image up a little in the frame to see the smile. It looks like an upside down rainbow-an "un-rainbow".
Scroll down to see it full size.

Solar halo

It's rare that stepping out of your front door you see something you've never seen before. This turned out to be a "solar halo" - a phenomenon apparently caused by sunlight cascading through ice particles very high in the sky.
A frozen rainbow perhaps. But my kids preferred to call it a sky smile.