Hi Werner,
a BIAB chordsheet with lines and chords won’t fit into a album cover art jpg.
Mp3 players usually have a small screen resolution, so the covers are 200x200 pixel or so.
And BIAB can’t save chordsheet to jpg.

You have to use Windows Paint or something like that.
Suggestion: Use MS Word, write down the chords in a large font, then save a screen snapshot to jpg. Windows 7 brings the “snipping tool” to do this.

Ralf