A smiling cartoon face is drawn with D3.js, rendered as SVG shapes. The face uses circles for the head and eyes, rectangles for eyebrows, and an arc-based path for the mouth. The eyebrows animate by moving downward and back upward over six seconds using chained `transition` calls with a 3000-millisecond duration. The code constructs the face using `d3.select`, `d3.arc`, and `d3.transition` APIs on the SVG canvas.