One decent option would be to embed the images in the nmap xml output, but output an HTML file that could parse that xml and display the images. I dont' think this is easily doable with local files in a browser.
But, there are still some improvements needed:
Images should be de-duplicated, and each host that has the same screenshot should be grouped. This will shrink the filesize and make validation of the targets easier (i.e. checking default creds)
It would be nice to have additional script for filtering, sorting, de-duping (if necessary).
One decent option would be to embed the images in the nmap xml output, but output an HTML file that could parse that xml and display the images. I dont' think this is easily doable with local files in a browser.
But, there are still some improvements needed: