A face built from SVG circles and a D3 arc path responds to the mouse position. The multi-component React app, using `useState` and `useCallback`, tracks cursor coordinates and renders a simple circle. The face is composed from `BackgroundCircle`, `Eyes`, and `Mouth` components, with the mouth generated by `d3.arc()` and the face assembled via `FaceContainer`. The code defines a yellow circle with black stroke, black eyes, and an arc-shaped mouth, all arranged in a fixed layout.