What do you mean by left right inversed?

Images are inversed, i.e. the right part of an object appears on the left in its images, and the left part of the object appears to the right. For example, the word 'AMBULANCE' is painted left-right inversed on the vehicle so that when the driver of a vehicle in front looks into his rear – view mirror, he can make out the word AMBULANCE quickly and give way.