Are time-lapse photography the same as tilt-shift photography? What is the principle? Why do the scenery look so small and toy-like in the photos?

Completely two different things.

Time-lapse, equivalent to taking a selfie.

You can talk about shifting the axis. In an ordinary camera, the optical axis of the lens is perpendicular to the film plane and at the center. Tilt shift is to move the optical axis of the lens away from the center of the film. Tilt-shifting cannot change the perspective relationship, nor can it change the focal plane, but it can capture positions that cannot be captured normally.