This example demonstrates how D3 transitions can animate the properties of an SVG rectangle. An initially short, 100-pixel-wide rectangle grows in height from zero to 400 pixels over two seconds after a one-second delay, while its fill color changes from steelblue to a warm orange in a second transition. The code uses D3 v5’s `d3.select` to append an SVG element, `selection.append('rect')` to create the shape, and chained `transition()` calls with `.delay()` and `.duration()` methods. The rectangle is rendered directly in the browser via SVG, with all styling and timing defined imperatively in JavaScript.