Signatures are based on your profile. Thus, if you have a personal profile for Claimlane, you can create a personalized signature for your responses in the chat.
You can define a signature individually for b2b chat and for b2c chat.
From your account, click your profile icon, and select "Administrate account".
From here, click "edit profile" and change your personal signature for the b2b and b2c chat.
The signature allows text and links. Not images.