To be honest, I have no idea how this picture was formed. During the night, the temperature was below freezing. What likely happened is the water vapor in the air, condensed and stuck to this grill. As the water froze on the grill, it created these crystal shapes. Other possibilities of it actually snowing can't be true because nothing else had this ice formation on it. My only question about these mysterious ice crystals is, how are there small spots on snow on the ice?