That's wierd, my S7 from AT&T came in a Samsung box.
That's why I'm curious that perhaps AT&T has two different boxes... not entirely sure.
As if one from retailers such as Best Buy, Target or Sams and one from their AT&T Stores. It just doesn't make sense that all the darn carriers decided to use Samsung boxes, but AT&T goes the alternate direction as if customers prefer AT&T boxes..