Why does a mirror allow us to see the image of objects?
The explanation is linked to the regular light reflection, which happens on very smooth and polished surfaces, such as a mirror, silver or stainless steel tray, window glass or standing water surface.
When light rays are regularly reflected in a flat mirror and hit our eyes, we cannot realize that these rays were reflected off the surface. We get the impression that they came from inside the mirror, exactly from where we see the image.
The calm surface of a lake allows regular reflection of light and the formation of images.
Our body is not a light source. It can be seen if it is illuminated because it reflects light diffusely, much like a notebook or a wall.
When we look at ourselves in a mirror, we can see an image of our body because the rays of light that are reflected (diffuse reflection) by our body reach the surface of the mirror, undergo regular reflection and reach our eyes.
Have you noticed that when we look in the mirror, it looks like the right and left parts have been “swapped”? And that goes, not only for our body, but for any object reflected in the mirror. In scientific language we say that mirror causes reversal of images, that is, it "shifts" the right and left places.