A face is drawn as a single circle centered within an SVG canvas, with its radius set to half the SVG's height. The example demonstrates basic D3.js v5 selection and attribute manipulation using `select`, `append`, and `attr` to position the circle dynamically based on the SVG's `width` and `height` attributes. The SVG is rendered in the browser with no external data source, focusing on simple geometric shape creation through D3's declarative API. The circle's center is computed from the SVG dimensions, and a CSS rule hides page overflow for a clean full-viewport display.