Avatars images are set on a per organization basis and displayed based on messenger configuration.
Log into portal and go to the “Configure Messenger” section. The image can be uploaded to the “Messenger Avatar URL” field in the “Customize Messenger Section”
The avatar is shown based on a parameter passed to the ServisBOT.init call when the messenger is being setup.
You can pass “displayAvatar: true|false” in your ServisBOT script.