This example shows a cartoon smiley face built entirely from basic SVG shapes, rendered inside a fixed 960×500 coordinate space. The face consists of a brown circle, yellow eyes with black pupils, grey eyebrow lines, and a D3 arc used for the mouth. The code uses React 17 to define the component and renders it to the DOM, while D3 v7 provides the `arc` generator that computes the mouth’s path with a start and end angle. React handles the SVG elements declaratively, with `stroke-width` and positioning set via attributes.