Display method and display system

A display system comprising:

• a camera imaging a range containing a display surface;
• and
• a display apparatus executing
• acquiring a first captured image by imaging the range using the camera,
• acquiring a second captured image by imaging the range using the camera after acquiring the first captured image,
• acquiring a first brightness value indicating brightness of a first bright point contained in the first captured image by a reflected light from a pointer for drawing a line on the display surface, and a first position indicating coordinates of the first bright point in the first captured image,
• acquiring a second brightness value indicating brightness of a second bright point contained in the second captured image by a reflected light from the pointer, and a second position indicating coordinates of the second bright point in the second captured image,
• displaying a first display image not containing a drawn image showing the line by the pointer on the display surface in a third position corresponding to the second position in an image displayed on the display surface when a first condition that the second brightness value is larger than the first brightness value by a first threshold or more and the second position is a position closer to the camera than the first position is satisfied, and
• displaying a second display image containing the drawn image in the third position on the display surface when the first condition is not satisfied.