I think I understand now. So I will replace line 34 of my server code with:
self.wfile.write('<img src="http://10.x.y.z:9090/stream.mjpg" height="240px" width="320px"/>')
and thread the server_serve_forever() statement, so that the pi can simultaneously process and set the images in a global variable, perhaps a queue.
So just for clarification, there isn't much I will have to do on my end other than set up a mjpeg stream with an appropriate send port and ip address. The smart dashboard will do the rest by finding the url and grabbing the images.