The center is the middle point of a picture, which often attracts the viewer’s attention and creates a sense of focus or importance. Bang explains that the center of a picture is a natural focal point, and the placement of elements in relation to the center can influence the viewer’s perception of their significance or hierarchy. Centering or symmetry can create a sense of balance or stability, while off-center compositions can create a sense of dynamism or tension.

In Picture This, diagonal shapes or lines are described as those that are slanted or tilted, deviating from the horizontal or vertical orientation. Bang emphasizes that diagonal elements create a sense of movement, tension, or dynamism in a picture, as they suggest instability or potential energy. She relates this to the idea that objects in nature that are positioned on a diagonal, such as falling trees or sloping hills, are often associated with motion or change. Bang also notes that diagonal lines can be used to guide the viewer’s eye through the picture, creating a sense of depth or direction.

In art, a diptych is a work consisting of two panels or plates that are hinged together, often used for altar paintings or other decorative purposes.