The rear view mirror on the passenger side of a car is designed to be convex, which means it curves outward. This design choice is made with safety in mind. A convex mirror provides a wider field of view, which helps to reduce the driver’s blind spots on that side of the vehicle. However, this also causes a slight distortion in the way objects are reflected. As a result, objects appear smaller and therefore seem farther away than they actually are.
This is why you often see the warning “Objects in mirror are closer than they appear” on passenger-side mirrors. It’s a reminder that the reflection does not accurately represent the distance of objects behind the car. The driver’s side mirror, on the other hand, is flat and gives a more accurate representation of the distance of objects reflected in it.