Coolest toy..

I was browsing through Target Toy sale catalogue (yes, like most 21yr olds would do. lol), and I have to say I was very much fascinated by this one toy in particular..

Fisher-Price Puppy Grows & Knows
$99.95

Puppy grows to full size dog in 4 days. Can magically become a puppy again. Talking puppy knows when it's brushed or fed. Puppy knows your name and when it's your birthday. Watch me grow! As seen on TV. New.

Can someone please care to explain how this works?? Is it like one of those Chia pet plants? lol! Kudos to Fisher Price for such innovative toy..!