A grid of steel-blue rectangles represents salary data from a CSV file, where each rectangle is drawn for a row in the dataset. The visualization uses D3.js selections to bind data and append `rect` elements, with hard-coded dimensions of 300 by 500 pixels. The code loads the dataset via `d3.csv`, parses the count values as numbers, and renders all entries without encoding the salary ranges or counts into the rectangle sizes or positions.