If you are looking to change your profile picture then the only option to change your profile picture is by importing it through Facebook.
 
If you wish to change your profile picture in the game, you need to connect to Facebook to have an actual picture.
 
Once you do that, you need to follow the below steps to change your profile picture:

- Tap on your icon on the map or the Level Bar
- Tap "Change Photo"
- If you are looking to update your profile picture to the same as Facebook, click the refresh on your photo (the green box with 2 arrows)
- If not, you can swipe through different color options
- Tap "Confirm" once you have made your selection.