A yellow smiley face is drawn on an SVG canvas, centered with fixed dimensions of 960 by 500 pixels. The face consists of a large yellow circle with a black stroke, two black eye circles, and a mouth arc created using the `arc()` function from d3. The React app employs ReactDOM to render the SVG elements, while d3.v6 provides the geometric path calculations for the mouth, and all coordinates are positioned relative to the center via SVG transforms.