We've made improvements to the way the site generates thumbnails. Thumbnails will now generate much faster and consume considerably less memory, especially when dealing with animated GIF. Previously, animated GIFs would not properly render a thumbnail. That has been fixed, and thumbnails will now use the first frame of the animation for a thumbnail. What did it fix? Check the above before/after example. From violent spaghetti to a work of art! We're hoping the performance/memory improvements also help resolve rare issues where the site's thumbnail occasional stutters, causing thumbnails not to display. We will be monitoring. NOTE: This does not resolve the long outstanding issue with custom thumbnails. We are still working on that.