In an interview given many years ago, Alex Toth advocated that comic artists should "plus" a script when converting it into drawings. The term comes from animation, and refers to enriching a story by inserting visual bits--background details, poses, actions--that don't appear in the script.
It's similar to what happens in movies. If a scene features two actors talking, the actors seldom just stand there and yak at each other. They'll perform some sort of business that tells something about their character while adding movement to a static scene. For some reason, though comic artists frequently enliven scenes with interesting camera angles, they often don't go much further.
Recently I re-read two stories that showed what a master Toth was at plussing a scene. One was from the 1970s, when he was drawing romance stories for Charlton; the other is a Dell movie adaptation from the late 50s. Before looking at the Toth panel, let's look at a typical dialogue exchange from another story in the same issue. The penciller is Charles Nicholas.
Creating well-thought-out backgrounds is a great way to plus a script. Consider this panel from the Dell adaptation of Clint and Mac, a youth-targeted mystery-adventure set in London. It's easy to picture the script for what might have been a throwaway panel. Smith, the guy in the trench coat, returns to his apartment expecting to meet his accomplice Toby. Smith calls out but Toby isn't there. Here's how Toth interpreted the scene:
Still one might ask, "Is there a point to this?" It's a fair question. After all the Clint and Mac panel really was incidental to the story. Its basic idea could have been got across in a simpler way. Is Toth just showing off? Comics as a medium are admittedly less involving than movies. People tend to read them quickly without scrutinizing each panel. However I believe that, just as happens in movies, thoughtful plussing subliminally adds to a reader's experience of the story, allowing him or her to take away from it more than was originally there.