Some people are very sensitive to flashing, flickering or rapidly moving content. For many they are a distraction but for some they can cause seizures. Seizures can be dangerous, or even life-threatening. Also, some visually impaired users may use screen magnifiers which would increase the size of the flashing content and intensify its impact.
If possible, avoid using video content on the page that flashes, flickers or blinks rapidy. However, if flashing, flickering or rapidly moving content must be used then try to restrict both the size of the video and rate of movement.
No example is available.