Two React-based face visualizations showcase the integration of D3 with React's declarative component model, where faces are constructed from reusable SVG components like `BackgroundCircle`, `Eyes`, and `Mouth`. The `Mouth` component uses D3's `arc` API to generate a path, while a separate globe visualization employs `d3.geoOrthographic` projection with `d3.geoPath` and `d3.json` to render world map data from a remote JSON source, featuring interactive drag and zoom capabilities.