Design AtlasAn indeterminate loader that leans on a shape's metaphor — "time is passing" — rather than abstract motion. The remaining time is just as unknown as with any other indeterminate loader, but because an hourglass is a familiar symbol, people unconsciously read it as "this will take a while," so using it for a task that actually finishes in a couple of seconds overstates the wait.
Two triangles meet via clip-path (or a border trick) to form the hourglass outline, with a small dot looping a fall from top to bottom in between; at a fixed interval the whole shape flips 180° in one instant step. Timing the flip to land right after the dot finishes falling keeps the "it flips once the sand runs out" logic intact.
It fits a genuinely long batch job or a processing queue well; for a loading state covering the whole screen, a skeleton still feels faster. Give the wrapper role="status" and aria-live="polite", and hide the shape with aria-hidden="true" since it's decorative. Under prefers-reduced-motion, freeze the flip and the falling dot and fall back to a static hourglass icon.