@Iconfactory @bigzaphod I said that because it was the only place the behavior was present.

In the release notes for the latest build, you mentioned: “Attachment thumbnails in the composer now play/loop for videos and animations”, which implies they didn’t before.

Also, I have “Auto-Play Video Previews” disabled in Tapestry settings. I think this setting should also apply in the main composer view and the alt text writing view, not just the timeline.