Photojournalism is the art of explaining this using pictures or photographs. One of the main examples are magazines and newspapers.
The action of Schaffer dismissing the sighting of smoke caused the fire to grow, for he did not bother to alert anyone else. Neither did he try to do something about the fire.
Another term for introduction is an exposition.
exposition: the part of a play or work of fiction in which the background to the main conflict is introduced.
Put a photo up for more explanation.