Slowed down, with a pause between lamps: each one only blinks on and off where it is.
Tricks of motion
Beta movement
Is a light moving around the square?
No: each lamp only blinks on and off in turn. The dim lamps never move.
Why? When lights flash on one after another, your brain fills in the movement between them. Every film, cartoon and moving news sign works this way.
Picture: Drawn by Science Playground · Wikipedia(opens in a new tab)