Hi Gary and welcome to our forum!
Off the top of my head, you could use a digital signature to sign the form and get the image that is used during the signature process before submitting to the data connection. That would require installing digital signatures for the users though, which is a high bar. The image that you refer to is actually a variant of HTML, so it's really not an image. To eliminate the attachment or customize the send you can create your own e-mail submit adapter and write code to control the various envelope parameters. Good luck!
Patrick Halstead [InfoPath MVP]
InfoPath Dev Seattle
Patrick Halstead
Project Manager at Qdabra