If you are using the poker app, you can change your avatar by hovering your cursor over the avatar icon in the upper left corner of the screen. A menu will appear where you can select ‘Change avatar’:
You will be taken you a menu where you can choose a new avatar to personalize the way others see you in-game.
In the browser version, you can click the menu icon next to your avatar in the upper left corner of the screen. Next, please click ‘Settings’ and then ‘Choose avatar’ in the next menu: