This example displays a large smiley face in a black-and-white gradient, with khaki-colored eyes and a curved mouth, centered on an SVG canvas. The face’s fill and stroke use two linear gradients defined in SVG `defs`, while the mouth is drawn using a D3 `arc` generator with specified inner and outer radii. The component is built with React, rendered via `ReactDOM.render`, and computes all positions and dimensions as JavaScript constants. The chart demonstrates integrating D3’s shape utilities, such as `arc`, within a React-rendered SVG hierarchy.