The essence of an image is representation, which is the same essence at the core of a symbol. Images are used to represent the external likeness of something, or convey an abstract ideal, or both. The same could be said for a symbol. Symbols are objective in their purpose, used to infer the same idea continuously. Images are subjective, left open to interpretation. Symbols and imagery go hand in hand (though a symbol implies a particular conclusion, the image does not, the image merely implies partial understanding). They are both tools to communicate, equivalent to words that are also a tool to communicate.
Now let's take a moment to dissect our language... Scratch that. Let us dissect our interpretation of language. People had language before they developed writing, so let's look at how we convey language separate from the verbal articulation of thought. We write letters; Symbols to represent thought. We use an intricate system of objective images to illustrate our words. Though these symbols are fixed, constantly the same, they are images non-the-less. Though instead of portraying vast scenery, vibrant colors, aesthetically pleasing visual stimulation; our words portray human concepts. Letters with fixed meanings to spell words with fixed meanings used to illustrate intangible ideas that exist in the realm of thought.
The very innovation of writing thought to a scribe is achieved by an elaborate system of imagery.
"The unconscious mind should be called the super-conconsious mind."