You Click 'Set As Profile Picture' In The Bottom Right Corner . Then You Crop The Picture , Then, you Press 'Done Cropping' And It's Your New Profile Picture .
Surprisingly not really but if you are referring to make this certain picture your profile picture then just click on our picture and at the right of the pic at the bottom it says1. Share2. Tag this...
Go to settings in the top right corner underneath your name. There at the top left you will see TwitPic and then under that there should be Mobile, Privacy, and Manage. Click on the Manage tab. Then...