So I guess add a fourth field, , defined as a brief textual description of the cover art. This will be optional (so as not to invalidate all the existing ifiction files) but recommended.
The update is to section 5.9 of the Babel document.
And, to reiterate what I said in a different post, you can stay on top of discussions like this on this mailing list: babel-if@googlegroups.com . (But I don’t expect a lot of discussions like this.)
much better than what I pictured. given the original request, I thought something like “Big giant title in stylized white font over a dark blueish forest background with a B&W teenage emo girl holding a red apple upfront.”