I set them last night, and I'm not sure how long it takes for those to show up on other instances. I am curious though, so if you wouldn't mind dropping a comment if/when you notice the new icon/banner show up on your instances.
The winner of the pos-mens is @[email protected] for the banner and for creating the animated icon. Honorable mention to @[email protected] for the inspiration for the icon.
Darn. I think the animated icon is affecting the 30 Rock banner, but Astronomy does not have a banner, so I can't use that to help troubleshoot. The 30 Rock banner looks great everywhere else, just not in Thunder.
When you favorite a community or add it to a group, it captures the community details at the time and stores it in your profile. If you un-favorite and then re-favorite it, it will update to use the community's current values.
I've been meaning to re-implement how groups/favorites are stored since it keeps a lot more information on hand than is really needed. Guess I'll bump it up in priority on my to-do list.