Shops use convex mirrors for security. What kind of image do they form and why does that help?

1. A convex mirror is a diverging mirror and forms only one type of image, a virtual one. 2. That image is upright and smaller than the object, for every object position. 3. Because the image is smaller, a larger area is imaged than a flat mirror of the same size would show. 4. Covering more of the shop from one mirror is exactly what improves security. 5. No convex mirror gives an inverted image, so both inverted options can be ruled out at once. _Source: OpenStax College Physics (CC BY 4.0), Ch 25 "Geometric Optics", section 25.7 Image Formation by Mirrors_