A simple, animated face rendered in SVG. The face consists of a yellow circle with black outlines, two white eyes with pupils, and a mouth drawn as a half-circle arc. The left pupil is positioned statically, while the right pupil animates horizontally across the eye using a D3 v5 `transition` and `duration`. The code constructs each shape with D3 selections and attributes, using the `arc` generator for the mouth.