The visualization displays horizontal bars representing headcount across nine U.S. cities, with each bar’s width scaled proportionally to its population count. The code loads data from `locations.csv` via `d3.csv`, converts the percentage columns, and then uses D3’s `select` and `data` join to append styled `div` elements with class `bar`. Bar widths are calculated by dividing the headcount value by two and setting the result as the CSS `width` in pixels. The bars share a uniform teal background and fixed height defined in the external stylesheet.