User blog comment:Rupert Giles/Introducing Updated Global Navigation/@comment-24001421-20140924211204/@comment-14310002-20140924214121

Well for you're first question: Your wiki probably isn't a test wiki and will not appear until it is globally released, next week.

Second: I don't think that would work. The header appears on every wiki for you, and they want to stick with a default theme/look.

Third: It looks smaller now for some reason. It might have just been a bug.