A D3 visualization renders annual temperature anomaly data from a CSV file as a series of rectangles. The code imports `select`, `csv`, `scaleLinear`, and `max` from D3, and uses an SVG container. The `scaleLinear` function defines an x-axis domain based on the maximum year in the dataset, though the scale's range is not set. The rectangles are appended to the SVG with fixed width and height of 300 pixels, without being positioned or bound to the data values.