Spoken and written word is often misheard or misread and also misunderstood, pictures and visuals may be effective in improving understanding when communicating new or complex ideas to people. It may be that pictures are used to compliment text, for example, when explaining a self management procedure such as giving an injection or caring for a wound it may assist people if they have it explained to them in words but also shown what to do using images.
In some cases, pictures alone may be enough, but pictures alone should only be used as an option where you are sure the person has enough understanding and knowledge to interpret it correctly. Ideally, as with written materials, pictures should be used to assist and support explanations not to replace them. One outcome which has been identified in the use of pictures is that they support recall, people are more likely to recall information they have been provided with if they receive pictures in addition to written or spoken information.