Please facilitate me? why does stores have those partially sphare shaped mirrors on the wall.

why does stores have those partially sphare shaped mirrors on the wall.
Answers:    They give the storekeeper a far-reaching view of the store and gross it easier to spot a shoplifter or other suspicious activity minus seeming to be watching everybody closely. It also helps me to see if anyone wishes help, if I own my back turned to the room. I enjoy one in my store, and I use it
they cover the security cameras so that you don't know which direction they are pointing contained by.