Club Penguin has accidentally uploaded the file of an upcoming pin. There is a new pin coming out next week, so it is likely this is their next pin that will be hidden, although it’s possible that it could be available as an item at the Fair. I’m guessing the first option, however. The pin is the Pixel Penguin Pin. Here’s an image of it:
I wonder what room it will be hidden at! I just hope it’s tiny again. :)
Thanks to Saraapril for bringing it to my attention.