This example builds a smiley face using React and SVG. It defines reusable components for the face's background circle, eyes, and mouth, which are then assembled within a central `FaceContainer` that handles the SVG coordinate system. A yellow circle provides the base, with black eyes and a mouth drawn using a D3 arc, which creates a smile by sweeping between specific angles. The face's proportions are controlled by configurable parameters like eye offset and mouth radius, allowing for easy customization.