Giraffe: Why Facebook profile picture changed to Giraffe?

Why Facebook profile picture changed to Giraffe?

Giraffe, Giraffe, Giraffe, everywhere.

I was using facebook and sudenly noticed that my friend change his photo into Giraffe's photo, will maybe he like that; few minutes later 1 more friend with Giraffe picture, then one more with Giraffe picture and I feel that All the zoo cams to my facebook account and my all friends changing into animals hahahaha. what was that? I saerched a lot I thought maybe it would to save Animals, maybe part of any campgain, but it was not. 

So what? are they crazy about? 

I just google and found the answer, maybe wrong or right. Actually riddle is questioning game. in this game  a statement or question  having a double or veiled meaning, put forth as a puzzle to be solved.

some example of riddle:

• What gets wetter and wetter the more it dries?
• What can you catch but not throw?

 all of these type of question and maybe someone bit on a question that if you don't win your profile picture will turn into Giraffe Photo or giraffe picture. seems funny? No? Yes? NO? I am going to change my facebook display picture to Giraffe Picture.