Purposeful, mediated design that is intended to persuade an audience through various appeals.
I’ll take issue first with the word purposeful. If that’s the word I’m going to use to define visual rhetoric, then it follows that visual rhetoric is not something that happens incidentally or by chance. In other words, I may propose a design to persuade an audience of one thing, but what if viewers become convinced of something entirely different or unrelated to the original purpose I intended? The original design might have been purposeful, but what if the design fails, or, rather succeeds in a way not intended by the rhetor? Does purpose even matter?
I suppose when I use words like “purpose” and “intent” one of the things I’m doing is working to exclude non-human agents from the discussion of visual rhetoric. Is a beaver dam an instance of visual rhetoric? There’s purpose behind its function, that’s for sure (safety from predators, a way to store food, etc.) But it would be difficult to say the design of the dam had some sort of purpose if I couldn’t figure out the beaver’s design intent.
When a peacock is looking for an opportunity to mate, is that a form of visual rhetoric? The tail feathers are sometimes visually rhetorical, a medium through which the peahen is either persuaded or not. At other times, the tail feathers are nothing more than an appendage, and if too large an undesirable appendage at that makes it difficult to outmaneuver a raccoon.
Pushing the thinking further, what about a stand of trees or a thicket as visual rhetoric? If it persuades a rabbit to take shelter when being chased by a cat, can’t it be said to be visually rhetorical? I had this discussion with a colleague and she insisted there was something fundamentally different about the natural world, that visual rhetoric must include some sort of human agency. But to that rabbit, the thick stand of blackberry stalks is pretty convincing. The message to the rabbit is not mediated, but then, without a predator nearby, the blackberry stand doesn’t send much of a message, or maybe a different message entirely, to the rabbit. Going back to the start, then, maybe visual rhetoric is defined as much by the viewer as by the designer, regardless of purposeful intent.