There isn't any special configuration in the widget required for an agent image. If you're having trouble with it after following the instructions in the link above, I'd suggest opening a ticket with PureCloud Support to investigate.
What image did you get. We are getting the default image but not the one we uploaded. Can you help us understand how the agent image is determined and used via the widget tools? Is there a different image for web chat we cannot find that as the interface does not have a spot in the person_agent section for a different image for chat.