As with water, constraints of communication materials are often social and historical (Wysocki 56);
What is unavailable in these images? How does a social and historical context inform them? What are we asking of the audience when presenting them? Sometimes an image can be a record of a precise moment in history, yet without knowledge of that history, it loses much of its significance. Even a computer generated logo has the ability to engage in a complex discussion of the social. But as with words, a language must be shared among the audience in order to elicit the desired response.
An image calls for words, and words produce images; they cannot be separated.