A circle at the center of an SVG canvas responds to mouse movement within the viewport. The React component tracks the pointer’s coordinates via the `onMouseMove` event handler, logging them to the console, while the circle itself remains static at the center. The visualization uses React 16.9 with hooks (`useState`) and renders directly to SVG, with the circle’s position fixed by hardcoded `cx` and `cy` values. No mouse-following behavior is implemented in the visible code.