This change will offer twitter user to know more about people via photographs they upload. This is a new addition apart from your profile photo and background photo.
Twitter new profile will empower self branding, there is also a Me tab for which i awaited from a long time since it allows you to see your own profile with one single click. Previously to check your own profile you need to click on your name.
The new header looks some what similar to facebook profile picture
Check out more on
How to post pictures/photos on twitter quickly
What is twitter for Dummies