Objects in a side-view mirror are not actually closer than they appear. The image in the mirror is simply a reflection, and reflections appear to be reversed from their original position. This can make it seem like objects are closer than they actually are, but this is an illusion.

The distance between an object and its reflection in a mirror is always the same. So if an object is 20 feet away from a mirror, its reflection will also be 20 feet away from the mirror. However, the image in the mirror will appear to be only 10 feet away, because it is twice as far away from you as the actual object.

The same principle applies to any type of mirror, whether it is a flat mirror, a curved mirror, or a rear-view mirror. The image in the mirror will always appear to be closer than the actual object, but this is just an illusion.