Cool.
If you look at it frame by frame in an animation editor it's part illusion, part subliminal.
1. Frame 2/12 has a green mark just above the dot at 3 O'clock.
2. Frame 8/12 has a green mark just below the dot at 9 O'clock.
3. Frame 10/12 has a green mark just before the dot at 11 O'clock.
4. Frame 11/12 has a green mark just before the dot at 12 O'clock.
If you stare at the above listed dots, you can see the green marks.