Why is one ray of light emanating from it not enough to build an image of a luminous point?

The image of a luminous point in a flat mirror is the intersection point of the extension of the rays reflected from the mirror surface.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.