Mine have similar faces and their patterns really change depending on the individual snail. I have one that actually came out of the tank (I have a full lid so I am not sure how she did it) and I found her on the hardwood floor with a cracked shell. I was so upset and had no clue how long she sat there (or why my cat didnt eat her). I put her back in the tank and she didnt move for a day. I thought for sure she would die, but she came around and is back to normal. That was a month ago.
Now her shell has a crack that has since sealed itself up, but it left a mark. They can have many different markings depending on their lifestyle or things they have experienced. I give mine algae wafers and they have grown quit a bit. I think they will still go after the plants as they never seem to get full.