This screams ''Early 70's'' (in a good way), and lets you know it's a comic advetnure. But the text is completely unnecessary (enzyme action, really?). Another possibility might have been showing Roz and Darren McGavin handcuffed together with raised eyebrows--could have drawn in the "date movie" crowd.
SheQuon
The paperback book at the time had a picture of Roz riding a donkey. This is more vivid.