This example renders a smiley face as a React component using SVG circles. The face consists of a yellow head with a black stroke, plus two dark eyes positioned symmetrically around the center of a 960×500 viewport. The code defines numeric constants for dimensions, stroke width, eye offsets, and radius, then passes them as props to the `<circle>` elements. It uses React 16.9 and ReactDOM to mount the SVG into the page, with styling that removes page margins and hides overflow. No interaction or animation is present.