Images play an ever-increasing role in the modern media. They are a key factor with the success of social media. Commericial images are plastered everywhere imaginable, enticing the viewer to take a closer look. They strive to create an emotion, an attachment, and ultimately (in the case of the advertiser), a desire to buy. It can be argued that images can evoke the emotions of a person to feel a certain way. But can they truly argue?
If images can argue, or in otherwords, pursuade, then they would be considered to be rhetoric, or more specifically, visual rhetoric. I agree with the way Aristotle defines rhetoric which is the "faculty of discovering in any particular case all the available means of pursuasion (emphasis added). In regards to images, there is a common saying that every image tells a thousand words. The question then becomes, do those thousand words try to pursuade?
Let's look at an example. Here are two images of tigers. The first image show a tiger wading through a stream. There can be a lot of connotations associated with this image. But there does not seem to be any specific argument made with this photo (unless you interpret it as arguing that if you let your backyard grow too wild it will soon be inhabited by tigers).
This second photo shows several men (supposedly poachers) holding a dead tiger. The argument is more clear. That there are poachers abroad and that tigers are not protected from them. 
The meaning of the first photo would be interepreted differently if seen now from the lens of the new information provided by the second image, or perhaps if there was a subcaption that said something along the lines of tigers being endangered by poaching. So in this case, the first photo doesn't really create an argument. But perhaps there is something more to images that is not being identified?
Some images have affect. According to Brain Massumi's journal, The Autonomy of Affect, "affect is unassimable" meaning that something is affective cannot be be put into words, it is something that is outside the realms of text. Affect precedes the intellectual when we encounter certain objects or images. Withing this realm of affect, there are two ways to judge an image- the studium and punctum. The studium of the image is what in the image that reveals the intention of the maker of the image. It often is revealed after some thought is applied. On the other hand, the punctum are the elements which arise out of the scene immediately and personally to the viewer. These elements are unique to the individual and are often difficult to put into words. They are more emotional than intellectual.
Not all images have the elements of punctum. What makes an image pursuasive can be that it is charged with punctum. It makes the viewer more emotionally attached to the image in a way that can be only unique the individual because it often bases itself from the personal views and experiences from the viewer himself. In this case, any text trying to direct the viewer to a certain conclusion about the interpretation of the image would be counterproductive for the punctum.
In my opinion, images can be visual rhetorical, but is not a common characteristic of all images. In order to be pursuasive, they must be charged affectively--they must have punctum with which the viewer can make a personal connection.
The Autonomy of AffectAuthor(s): Brian MassumiReviewed work(s):Source: Cultural Critique, No. 31, The Politics of Systems and Environments, Part II (Autumn,1995), pp. 83-109Published by: University of Minnesota PressStable URL: http://www.jstor.org/stable/1354446 .
