When Live View is set to a multi channel display mode it is possible to switch the positions of the cameras to get the layout .
For example, when viewing cameras in a 2x2 display mode Channel 1 is automatically shown in the top left corner of the screen and Channel 2 is shown in the top right corner of the screen.
To switch the two channels simply click and drag one of the camera images onto the camera image you want it to swap positions with as shown below.
