Stopped at the flash: the two bars line up exactly.
Tricks of motion
Flash-lag illusion
When the bar flashes, is it in line with the moving bar?
Yes, exactly, though it seems to lag behind.
Why? Your brain predicts where moving things will be to make up for its own delay, but can’t predict a flash. Football referees fall for this when they call offside.
Picture: Drawn by Science Playground · Wikipedia(opens in a new tab)