by the looks of it, he has just added tips or extenders to the exhaust system.
That's where the exhaust actually are, if you too took that photo yourself you would see the original exhaust pipes from that position.
Its just those are longer and hang lower than the stock.
I would cut a grove into the bottom bumper lip to make it come out more straight .. Not sure how you would clean up the edges or getting a clean cut but I'm sure someone could do it . I'm thinking of doing something like that but the hidden pipes are slowly growing on me