A scatter plot of auto-mpg data shows the relationship between vehicle weight, horsepower, and fuel efficiency, with points colored by country of origin and sized by miles per gallon. The visualization is built with the Vega-Lite API, registering both Vega and Vega-Lite engines, and leverages D3’s `csv` module for data loading from a UCI Machine Learning Repository dataset. SVG rendering and tooltip interactions are configured through Vega-Lite’s `config` and `Handler` interfaces.