This example shows a yellow smiley face with two eyes and an arc-shaped mouth, rendered as SVG inside a React app. A dropdown lets the viewer toggle the look direction between left and right, which changes a wink eye’s position offset. The face is built with basic D3 shapes—`circle` elements for the head and eyes, and `d3.arc` for the mouth path—positioned using a centered translation. React manages the UI state, while the d3.v5 library handles the geometric calculations in an SVG coordinate system.