This example creates a simple smiley face using D3 version 7 and SVG primitives. A yellow circle serves as the face, with two small black circles and an arc for the eyes and mouth, all positioned and scaled to the browser viewport. The `onmousemove` event handler tracks the cursor, and the code uses `d3.select`, `d3.arc`, and SVG attribute chaining to translate and reposition the face’s features, making the eyes and mouth subtly follow the mouse movement in real time.