The word verism as it is used in context to Roman art is very simply defined as showing what is really there. Unlike most periods of art the Romans wanted to show there subject for what they really looked like. Back then this was kind of a bizarre concept. Today when someone want a photo of themselves all they do is take a picture and the photo captures everything you would see on that person as if you were standing face to face with them. However hundreds of years ago it was common practice for the artist to leave out imperfections and even add stuff that was not there to start with, like mussels. They would even portray themselves to be the same age their entire life. So even though they are in their 70’s the art made of them will depict them in their 30’s. Using the style that was common back then a king could have himself depicted however he wanted. However if you were put into art during roman times you were shown as you were no matter how revolting you where.
My theory is perhaps over time people came to realize that are of the past was not depicted correctly. So as people found this out maybe they made a connection that perhaps the story’s they represented where not all together true also. Perhaps people started to doubt what they were being shown in art. I mean if a man can make himself look fifty years younger than he really was whose to say that any of his stories were true either. Maybe he just had then all made up and then an artist portrayed it the way he wanted.
So perhaps in an effort to end this speculation from the public the Romans wanted to show everything accurately. This way not only did their kings look like really people but , their stories seam more likely to be true than fairy tale.