A smiling face built with SVG draws its features from geometric shapes, including a yellow circle, two eyes, and an arc for the mouth. The eyebrows are rectangles that animate upward and back down in an infinite loop using chained `transition` calls. The code uses `d3.arc` for the mouth path and D3 selections with `attr` to position elements. All shapes are appended to a centered `<g>` group within a fixed 960×500 SVG canvas.