@youtube please let me see the thumbnails for videos again. I sincerely hate this and it's effecting my experience with your website quite negatively. please, please let me see custom thumbnails again.
Appreciate your feedback. The experiment ends in a few weeks, we're just testing/improving custom thumbnails for those creators that use them. Here's more about this: https://goo.gl/A7oDmr . Thanks for your patience.