A yellow smiley face with animated eyebrows demonstrates D3.js DOM manipulation and SVG rendering. The code uses `d3.select` and `d3.append` to construct circles, rectangles, and a mouth path via `d3.arc`. Chained `transition().duration()` calls repeatedly shift the eyebrow group’s `transform` attribute, creating a bouncing motion. All elements are centered within a fixed 960×500 SVG viewport.