The avatar is selected automatically from a pool of available images. The selected photo is not visible to you, but all clan members can see it.

 If you want to add your own photo, you must do so by logging into your Facebook account.

You can log into your Facebook account in the following way: click on your avatar located in the upper left corner of the screen. The player's profile will then open. Once you are there, tap your finger again on the visible avatar, and then on the "login" button visible in the lower right corner of the screen.