Yesterday, I asked the question what is it and showed this picture:
Many people made many good guesses both here and on Facebook. Thank you all for playing, it was fun. It is a picture of a duck’s eye. The day was cold and gray and many ducks were walking on the frozen pond. This duck was swimming near me and she looks beautiful.
If you like, you can download the high-resolution picture. (It’s only for personal use and I retain all rights).