Did you stick another bar of soap on top of a brand new one? Then, if you wear down the backside of the bottom bar, you'll be left with that inside-out lettering.
you took the photo in a mirror
You were being dyslexic when you carved the letters into the bar of soap.
Use the side that doesn't say anything until it gets to the lettering?
Good job guys! Eli had the right answer to start with, but Joan's answer was clever and Moot's answer funny.