I didn’t know about it until you mentioned it here. I found the following link:
They even have a Facebook page.
It is authentic. if you join their FB page, you will see the weekly photos of all the contestants throughout the competition. As a matter of fact, I received a newsletter today in my email highlighting a few of the contestants! In my opinion, the pictures are posted for everyone to see so that everyone can let the contestants and trainers know that they are doing a great job.