In this quick tutorial, I will teach you how to make a Twitter background that shows up on mobile devices. See my sample here!
This is a new feature. Go to your settings to edit your profile.
Click on header and upload a photo.
You can take one on the spot or choose one from your photo album. Choose one where the subject is off to the side or a simple pattern or texture because your avatar will cover up the middle.
That's it! Have fun! Thanks to @billselak for teaching me first.