This example shows a custom smiley face built entirely with SVG shapes. It uses React to render a yellow circle for the head, two black circles for eyes, and D3’s `arc()` generator to create both the mouth and nose as filled paths. The arcs are positioned using start and end angles, with inner and outer radii defining their thickness. The face is centered on a 960 by 500 canvas, and the code specifies stroke widths and offsets for the facial features.