Input vs. Output
This is akin to the famous Magritte painting of a pipe, accompanied by the text ”Ceci n’est-pas une pipe” – this is not a pipe. Because the work is obviously a painting of a pipe, not an actual pipe.

This reminds us that an image is not reality, it is a reflection of, or an expression of reality. It may even be purposely created as something entirely different from reality: a fantasy, or an abstract concept.
Likewise, design is not reality, and it is in itself not the solution to the client’s need – it is simply an expression of that solution. The desired communicative outcome represents the actual solution: how the audience responds to it, and how they choose to act based on that.
What does this mean?
It means that, as designers, we should not design for design’s sake. The kind of visual expression that exists for its own benefit is called art.
Design is a tool. A means to an end.