I promise y'all pics when it was done, so here they are! It's concrete, dyed brown and drawn to look like flagstone. Yes, drawn. He drew in all the stones free hand, then textured them with a concrete stamp. He also grouted the lines to give it a more realistic look.
Please excuse the paw prints on the sliding glass door and the unkempt yard. Also, our house is not really pink, it just looks it in photos apparently!