A picture says more than a thousand words
Pictures have the following properties:
They can be quickly recognised and processed.
They are unique. This helps us to memorise them easily and retain them for longer.
They appeal to our emotions.
They provide a lot of information that would be difficult to express by purely linguistic means.
Our brains respond very strongly to pictures. Visual information takes priority over all other information. Neuroscience has a special term for this: the pictorial superiority effect. John Medina explains this phenomenon in his book Brain Rules by the evolutionary significance of pictures. Once upon a time people retained important (survival) information above all in the form of moving images. Whoever could process these quickly had an advantage. This explains why we react so strongly to pictures today and why visual information is so important for us.