Peter Wegner’s split flap piece at the Stanford business school, 2011. Split-flap displays (aka Solari boards) are the reason why departure displays for trains and planes are still in text mode. Each cell of the grid holds a collection of alphanumerical flaps or, as above, different colours which reduces it into a pixel display.
As they change they make sounds, which alerts the viewer. A similar thing (mechanical movement, tactile noise) is Daniel Rozin’s wooden mirror.