A pie chart displays the distribution of sales counts across different brands, with each slice labeled and colored uniquely. The chart is rendered as an SVG using D3.js v7, with data loaded from a CSV file via `d3.csv` and aggregated using `d3.rollup`. Slices are generated with `d3.pie`, and a legend positioned to the right shows brand color mappings. Hover tooltips are not implemented, but static labels and a Tableau10 color scheme provide clarity.