Funny Experience

Someone sent me a friend request on the social site Facebook. When i opened her profile, i found that the profile picture was of a man, and her profile name was also a mans name.  She also added her sex as a male. I was confused to see that. Then i asked another friend who that person was. Then he told me she is a female and our mutual friend.  Then i asked her why did you do that? Then she replied that she wanted to check if I would be able to recognize her or not.  The only hint was that she used her original surname with the mans name.