Hello,
you need to make your own custom tag, in which you can include an image component along with a message component.
I don't know the best tutorial, but you may find some on
JavaServer Faces (JSF) Tutorial Net in "Developing JSF Components" section. I liked the
How To Create Your Own JSF Components for basic understanding. You maybe don't need a renderer, create UIComponents as needed, for example a panelGroup with two children, a graphicImage and your needed htmlMessage.
Regards,
Thorsten