This example uses D3.js to construct a smiley face entirely from SVG shapes, including a yellow circle, two eyes, eyebrows, and a mouth drawn with an arc path. The code demonstrates fundamental DOM manipulation by selecting an SVG element, appending groups and shapes, and applying transforms. The eyebrows animate by chaining two `transition().duration(2000)` calls that shift their vertical position up and then back down, cycling through a curious expression. All shape attributes, such as radii and spacing, are defined as constants, and the face is centered using a translation based on the SVG's height and width.