A smiling face is drawn on a yellow circular head using SVG elements. The face’s eyebrows and mouth animate, moving up and down and scaling to create an expressive motion. The example uses d3.select to build the SVG structure and d3.arc to construct the mouth path. Eyebrow and mouth animations are driven by chained d3.transition calls with specified durations. The code uses a React setup and a bare HTML page, with all D3 functions applied directly to the SVG.