Zàijiàn means goodbye.
The person opposite looks at their watch to show that it is time to go: time (Zeit in German) gives you zài. The hand of that watch is sharply pointed at the tip – the point stands for the falling tone. On the dial, ducks are standing on skis, and their beaks are pointed too: skis and ducks (Enten in German) give you jiàn, falling again.
Two pointed details, two falling tones – the image carries the pronunciation along.