A smiling face rendered with SVG animates its eyebrows up and down. Built with D3.js v5 and React, the visualization constructs the face from basic shapes—circles for eyes, rectangles for eyebrows, and a path for the mouth—using D3's `select` and `arc` APIs. The eyebrows transition vertically via `transition().duration(2000)`, creating a playful, looping expression. The SVG canvas is 960 by 500 pixels, and the face is centered using a group transform.