If I create an image-type TV, give it the fred, fred.type and fred.media.source properties, it works as expected for non-Fred pages, and in Fred shows properly when selecting an image in the page’s Settings -> TVs tab.
However, when rendering in the page, the source’s path is prepended to the image’s full path, thus doubling the (for example) /assets/images//assets/images/…
If I change the TV type to a Fred Dropzone type, then Fred-rendered TV images work correctly, but non-Fred pages are missing the media source path. And, of course, you can’t edit those TVs in the Manager for a non-Fred page.
This isn’t the end of the world, just use non-Fred enabled TVs and edit them from the Manager. But the question remains, why does Fred double the media source path if using an ordinary image-type TV?