Smart loading indicator

Just a stretched thumbnail or gray placeholder is used, with the full image progressively loaded over top.

Luke Wroblewski on spinners:

“It’s like watching the clock tick down—when you do, time seems to go slower.”

If at least a tiny part of the image has not loaded for 1 second or a browser does not support progressive loading, a spinning progress indicator smoothly fades in. A delay is added to avoid blinking in case the image was cached or the user has a fast connection.