Twitter's updated, larger "header" images, which appear horiztonally in the top background of a user's profile, will be rolling out site-wide to all users as of December 12, the company announced on its blog Monday. Twitter urged users to upload a header image by then to avoid seeing "a default grey image on your page. That’s not fun!"
The new cosmetic feature, which first debuted as an option for users in September, makes Twitter more closely resemble Facebook and Google Plus, both of which have offered users the ability to upload their own large, banner-like images at the top of user profiles since January and April, respectively.
(H/T: The Next Web)