How it's made
Nothing in this scene is keyframed. It is seventeen rules between things — night is how low the sun is; the stars are as bright as the night; the moon is the sun mirrored; the boat sails after the sun; the gull circles the boat; its chick trails the gull; the sea reflects the boat — and the PinePaper engine works the picture out from them, every frame, in order.
So one drag travels: sun → night → stars, sea, lighthouse; sun → boat → gull → chick, and the reflection. The dashed lines are those links; each lights up while it is carrying a change. Cut one and only what depends on it stops. That graph is how a PinePaper design can be changed by asking — “make it dusk”, “let the boat lead” — instead of redrawn.
This is the real PinePaper player (the one that plays every embedded widget), running in your browser. Nothing you type is sent anywhere.