This example uses raw SVG and JavaScript to create an animated, mask-based optical illusion. It shows a single, complex blob-shaped path that is duplicated and used as a mask to alternately reveal and hide a grid of horizontal and vertical lines. The two mask layers, defined with inline CSS `@keyframes` animations, rotate the blob path in opposite directions, creating a dynamic interplay of shapes and lines. The visualization is rendered entirely in the browser using the Document Object Model (DOM) to construct SVG elements, with no external data sources or libraries.