I think that while the end result of media is to, ultimately, get a message across to an audience, visual media try to achieve that same goal as other forms of media do.
Print media focuses on written expression and for an idea or concept to be understood solely by reading an article/story. Visual media, such as television, video and graphic design utilise visual aspects to enhance or further explain a particular message.
Adrian Miles talks about the rise of videocasting and vlogs and how media has, rapidly, moved to incorporate visual aspects. He also says that there is as much diversity in style and content and technical excellence as in text-based blogging.
Also, visuals help make visible an idea or piece of information that is often hard to grasp. In that respect, visual media work differently because they must incorporate images, video and/or sound. For example, charts and graphs help visualise statistical data and the change of data.
A great example of this is presented here showing videos incorporating images, sound and text to visualise concepts that have commentary by experts in particular fields.
Visual media has a visual predominance. They aren’t exclusively visual as W T J Mitchell of the University of Chicago points out. Visual media involve touch, aural and visual.
Visual media presentation of the Stolen Generations
“Over the Moon” from the movie “Rent” of a performance art incorporating visual media to enhance the performer’s message