A yellow smiley face with moving eyebrows demonstrates core D3.js DOM manipulation. The code uses d3-selection to append SVG circles for the eyes and face, rects for the eyebrows, and a d3-shape arc for the mouth. Chained transitions animate the eyebrow positions over two seconds each, lifting the left brow upward while the right brow returns to its original spot, all within a fixed 960x500 SVG canvas.