1. An image presentation system comprising: a first head mounted display that comprises a detecting device that detects a position and orientation of said first head mounted display and presents an image to a user; a first drawing device that draws a 3D (three-dimensional) virtual space image seen from a point of view corresponding to the position and orientation of said first head mounted display and displays the 3D virtual space image on said first head mounted display; a second drawing device that draws a 3D virtual space image seen from a point of view corresponding to a position and orientation of a third party's point of view and generates the 3D virtual space image; a second non-head mounted display that presents a 2D (two-dimensional) image corresponding to the 3D virtual space image generated by said second drawing device to a person who gives an instruction to the user; a capture device that captures the 2D image presented by the non-head mounted display on the basis of a first user instruction and acquires the position and orientation of said first display when the 2D image is captured; an input device that inputs coordinate values of a 2D position pointed on the captured 2D image on the basis of a second user instruction to the user wearing the first head mounted display after the 2D image has been captured by said capture device; and a converting device that converts the coordinate values of the 2D position input by said input device into coordinate values of a 3D position in the 3D virtual space image on the basis of the acquired position and orientation of said first display, wherein said first drawing device draws a line segment object being extended from a focal position of an objective viewpoint camera to be displayed on said first head mounted display at the coordinate values of the 3D position in the 3D virtual space image such that the line segment object and the 3D virtual space image are overlapped.