There are two display windows at the top. The display window appearing on the right shows the texture mapping applied to the rectangle for the selected texture coordinates, wrapping options and environment mode. The vertices of the rectangle are set to fill the window. The display window to its left is provided for understanding which texels are selected for mapping.
The selected texels as shown in the left window are those within the magenta rectangle. When the wrapping option is Repeat for either texture coordinate, multiple instances of the image map are displayed. When one of the clamp options is selected, we see only one instance in the direction of the selected coordinate. See the discussions on the Selection Panel and Parameter Input window for the meaning and effect.