A tweet that I recently posted–which was retweeted over 1.5K times–featured a visual illusion called the Perpetual Diamond (see my December 2018 article in i-Perception, co-authored with Oliver Flynn).
The diamond is physically stationary but appears to move because of the contrast between the edges and the background. The perceived direction of the diamond can be controlled by changing the temporal phase of the edge modulations.
See how far away you can be from your screen before the effect disappears. The diamond moves even when the edges are really thin.