People remember pictures better than words, especially over longer periods of time. This phenomenon is called the Pictorial Superiority Effect*. “When we hear something or read text alone, we are likely to remember only 10% of it 3 days later. If that information is combined with a relevant image, we are likely to remember 65%.” (John Medina, Brain Rules, 2008)
*Nelson, D.L., Reed, U.S., & Walling, J.R. (1976). Pictorial superiority effect. Journal of Experimental Psychology: Human Learning & Memory, 2, 523-528.