Proximity means closeness in space. In a visual text, it refers to how close elements, or groupings of elements, are placed to each other and what relationships are built as a result of that spacing. The relationships created by the spacing between elements help readers understand the text.
Proximity
The purpose of proximity is to give the viewer a better understanding of what is being said. By putting the title at the bottom and the words "Some guys just can't handle Vegas" at the top, the viewer understands that these men are going to go through some drunken ordeal in Vegas. Along with this there are multiple credits close in proximity to the bottom. Because this format of proximity is closely followed in many movie posters the viewer knows that the title is separate form the credits.
In this image the use of proximity allows the viewer to understand that this is an image of a boy playing the guitar. Because each square is close in proximity it allows the squares to paint the picture of a boy.