A yellow smiley face is rendered to fill the browser window, scaled to the viewport dimensions using React and SVG. The face is drawn with a yellow circle for the head, two black circles for eyes, and no mouth, all positioned via computed offsets from the center. The code uses React 16.9 and ReactDOM to render the SVG elements, with window dimensions, stroke width, and eye offsets defined as constants. A commented-out static SVG version shows an earlier iteration with a fixed 960×500 canvas and different eye placement.