How do I configure a wide Twitter cover photo like the top image on this profile: https://twitter.com/Taupoweddings
I don't see it in my Twitter settings anywhere.
On Tuesday, April 8, 2014, Twitter announced they are rolling out a new personal profile design and that it will be "coming soon to everyone...in the coming weeks." So just hang tight and you'll soon be able to have your own version.
Additionally, here's a Wired article about the profile update, including some other new features like pinning tweets.
Simply go to your Twitter settings and change the "Header" by uploading a new file. The recommended size is 1500 px × 500 px.
You can also do it directly from your profile (assuming you're logged in).
More information at the Twitter Help Center.