A smiling cartoon face is drawn and animated using SVG primitives, with two eyes, eyebrows, and a mouth constructed from circles, rectangles, and a D3 arc path. The eyebrows repeatedly rise and fall via chained `transition().duration()` calls triggered by `setInterval`. Built with D3 v5, the code uses `select` for DOM access and the `arc` generator to shape the mouth, with all elements centered on an SVG canvas.