A year around the Sun.
Snapped at the same time each day.
Vasilij Rumyantsev says, “I should say it is the most complicated photograph I have ever made.”
“It shows the position of the Sun at the same time of day during one year…. photographed 36 times, every tenth day, exactly at 5:45, on a single frame of film.”
The tilt of the Earth traced by the Sun over the course of a year is called an analemma [wiki].