When you look at objects in a mirror, left and right are swapped over.

To see this effect, if you stand in a mirror and hold up your left hand, your mirror image is holding up their right hand.

Here is a photo of this effect, not that the rock int he mirror image is on the other side of the van, with respect to the driving position of the toy van:

This also happens with words, and this diagram shows how words are laterally inverted in mirrors:

This is why emergency services vehicles, like the Fire Brigade, write the name of the service in mirror writing on the front of the vehicle, so when drivers look in their mirrors, the writing looks the right way round.

This effect can be seen in the photo below: