This example demonstrates fundamental DOM manipulation with D3.js by constructing a smiley face from basic SVG shapes. The code selects the SVG element and appends a circle with a radius of 200 pixels, while the accompanying stylesheet hides body margins and overflow. Using D3 v5’s `select` and `append` methods, the visualization shows how to programmatically create and style SVG elements, with related video content explaining animated eyebrow movement.