Typically, a copyright transfer refers to the entire work and does not distinguish between artwork and text. Copyright law does not distinguish the various chronological states of a work as it is developed, whereby you might say that the text is really a series of 100 versions, each one being a derivative of the previous one. Instead, you have one whole work, the final product (the version of record). If you then want to recycle the text or graphics of that paper (beyond what is covered by fair use), you would need permission from the (new) rights-holder. You would need to scrutinize the language of the transfer agreement, but it is unlikely that any agreement also transfers copyright in earlier drafts, or elements of earlier drafts.
If an earlier version had a clearly different drawing which you also created, the courts would probably not find that you had transferred the rights to that drawing as part of the rights transfer of the version of record (assuming no explicit "and all previous works" clause). But if earlier versions had a minimally different drawing, it is reasonable to think that the courts would find distribution of that earlier image to be infringing. One of the main questions asked in an infringement case is whether the works are substantially similar. If your earlier version of the text has "But" where the published version has "However", the versions would be so substantially similar that the earlier version would be found to be infringing, despite not being a verbatim copy of the published version. The same goes for minor changes to drawings. The essential question, I think, is whether you have "the same drawing" versus "a different drawing", and I find it difficult to figure out where the bright lines are for substantial similarity in drawings.
