This example demonstrates fundamental DOM manipulation with D3.js by building an interactive smiley face. The code uses D3 selections and `append` to create SVG circles, rectangles, and a path for the face, eyes, eyebrows, and mouth. The mouth relies on the `arc` generator with specified inner and outer radii and angle ranges. The shape is centered using SVG transforms, while the face and features are styled with fills and strokes defined directly in the code. The visualization highlights D3's core capabilities for creating and positioning SVG elements without any data binding.