One of the characteristics of art (as opposed to craft) is depth. When one detail serves more than one function, then depth is added. And that adds an additional way to appreciate the art.
I know that most people don't think of comic strips as art, but look at these two recent sequences from Rex Morgan, MD, by Woody Wilson and Graham Nolan. (click on images to enlarge)
In the first panel of the first sequence, we see Rex and June Morgan walking along the boardwalk in conversation. In the second panel, the conversation continues as the couple stroll off to the right. In the foreground is an older couple.
Shifting perspective is very common comic strip technique to keep dialogue interesting -- otherwise you'd have a strip full of talking heads. After establishing who's talking in the first panel, the artist often uses second to provide further details about the scene by putting the conversation in the background. Ed Dodd artist/writer of Mark Trail often uses this as an excuse to do full panel wildlife portraits.
In this case, though, there's something else going on. Look carefully at the four figures. The older couple mirror the poses of the younger. Both couples in love, the commonality emphasized by their mirrored stances. Note also that Nolan didn't have all the heads at the same level, either. He could have drawn it that way to more closely match the two panels, but by having the older couple a little lower in the panel, it seems more natural. As people age, they shrink slightly in stature. By making the older couple appear shorter than the younger, Nolan makes a stronger connection between the two chronologically.
By itself, the sequence has an underlying theme of love through time. It's only the following day that the true purpose of the sequence is revealed. That couple in panel 2 has a medical emergency that Dr. Morgan responds to. So the primary purpose of panel 2 was to foreshadow the introduction of new characters.
We expect depth in the fine arts -- ballet, painting, classical music, sculpture, etc. But to find it in a medium that's considered disposable is remarkable. Nolan didn't have to draw that second panel the way he did. There were more prosaic ways to foreshadow (or even just break up the scene). Artistically, he did more than he had to. And that's something I appreciate.