In-vehicle display controlling device and display controlling method for improved display output of operations

A display controlling method, performed by:

• a display controlling device, for controlling display of at least one display that is installed within a cabin of a vehicle, including at least a processor communicatively connected to the at least one display, the display controlling method includes:
• acquiring a captured image wherein the vicinity of the vehicle has been imaged;
• setting a prescribed region between the at least one display and a position wherein a vehicle occupant is within the cabin of the vehicle;
• setting a display function chosen by the vehicle occupant from among multiple display functions as the display function associated with the prescribed region;
• detecting a position relating to a viewpoint of the vehicle occupant;
• and
• controlling the at least one display so as to display the captured image, wherein:
• when the position relating to the viewpoint is detected as being in the prescribed region, the processor executes the display function on the captured image displayed by the at least one display.