I think it's true because u must understand what they think before you know what to do
Let's break it down. The first part, Visual, is what you see when you look at something, color, arrangement, font, etc... The rhetoric part deals with the persuasion. In conclusion, it's what we see and how we act or think when we see it. It is one's ability to understand what an image is attempting to communicate.
I think is man i hope im right :)