Hello Ted! Unfortunately this is not possible "out of the box" in EPiServer 4.51. I added the following sugestion to the wish list: Issue #41633 - You should be able to set an image that should be used instead of a submit button for a xform. I'll also try to add an example of how to do this in EPiServer 4.51 as soon as I get the time so keep an eye open in the code samples section.

The code sample available requires upgrade to 4.60. Is there any way to solve this issue in 4.51?