The Single Shot mode of taking photos is when both lenses on the camera are taking the image simultaneously.
To use this mode, click on the camera settings option (…) from the default Quick Capture mode.
Notice how the two images of the camera now appears as one as shown below.
This is usually used when you wish to simply take the photo with just one click however, please bear in mind that this captures everything around the camera, including you.
So if you do not wish to appear on the photo, you can either hide behind a wall or step out of the room. That is of course, if you do not mind appearing on the photo.
From here, you would then name the room.
Click on OK when done!
You can use this mode if you are taking a shot of a small room where you are out of the room around a corner, roof or aerial shots, shots where there is a potential case of the camera moving and shots where you do not mind being in the picture.