Static images on a wall that appear animated as the train moves.
Seen similar in tunnels - stroboscope timed to match train speed. Which does work with naked eye.
@robchapman @marcioaleks the train moves, accelerates ; the camera takes pictures every nth second. This last step produces a stroboscopic effect our eyes (and brain) see as a continuous movement.
I mean this illusion is not visible with naked eyes, without stroboscopic effect. Daylight, you need a camera, or to blink your eyes; nightly, the artificial 50Hz light might make the magic happen.
PS: frankly, I keep being a bit skeptical about this movie. More than ever before, illusion can hide everywhere in the digital world. The fascinating part is that it could anyway help us understand the reality behind our senses.