The first entry you have is a Markdown link rather than an image, it’s missing a leading exclamation mark. When changed to be an image, this would have no chance of working on i*OS devices that have no Desktop, but it would reference a file on a Mac … though in my test I couldn’t get it to show in the Print using either no protocol or file. I don’t know if I’m missing something that you did or are proposing.
The HTML markup works for me in the in-dialog print preview on the Mac, but as noted, not in the action-based preview, which is what the thread has been about. Trying the same thing on i*OS, everything is going via actions so I wasn’t able to get the image to work on this.