A smiling face rendered in SVG using React components and d3’s `arc` function for the mouth. The face includes a grey blurred shadow via SVG filters, yellow circle head, black stroke, eyes, and orange elliptical freckles, all positioned with fixed constants. The React `App` component returns the SVG markup, and ReactDOM renders it into the root element. The code uses d3.v7 for the mouth arc and React 17 for component-based SVG construction.