What does the environment in the picture entity element mean?

It refers to subject, companion, foreground, background and blank space.

The main performance object in the main screen. Among the five elements, the subject is the most important and needs to be highlighted. Protruding subjects are mainly divided into direct and indirect subjects. The foil is the secondary performance object in the picture, which is closely related to the main body and only plays a foil role. Attachments are generally divided into tangible attachments and intangible attachments.

The foreground is generally located in front of the subject in the picture and closer to the lens. There are two kinds of foreground: fuzzy foreground and frame foreground. The background is generally located behind the subject in the picture, away from the lens. Blanking leaves meaningless parts in the picture. Proper blank space can make the picture more concise, the theme more prominent, and the audience's imagination more space.