Seven semi-transparent circles in vivid colors, such as pink, purple, and green, are positioned at fixed coordinates on a light gray background. The visualization uses D3.js v7 to render an SVG canvas that fills its container, with the `select` API joining circle elements to a static dataset containing x, y, radius, and fill properties. The circles are drawn with an opacity of 0.7, and the background color is configurable through the `viz` function’s options.