Earlier this year, Twitter revamped the profile pages for its users, adding a Facebook-style “header photo” on every one. Early adopters have been playing with the new feature since then, but now Twitter says every user’s profile will be switched over to the new design tomorrow (12 December). It’s reminding users that this means they may want to sort a photo out sharpish. “If you don’t upload a header photo by then, you (and everyone else) will only see a default grey image on your page. That’s not fun!” A message worth heeding for artists and music marketers in charge of their profiles.