A D3.js v7 scatter plot displays the Iris dataset from a CSV file, mapping sepal length to the x-axis and petal length to the y-axis. Species are encoded using different symbol shapes via `d3.symbol` and `scaleOrdinal`, with a custom legend for the shape categories. The visualization uses `d3.scaleLinear` for both axes, `d3.extent` for domains, and custom modules for axes and shape legend rendering, with margins and axis labels configured.