If you have two bar magnets opposing each other separately, then the field lines go from the north- to the southpole of one bar to the other. However, since there are two south- and two-north poles, the field lines seem have opposite direction for the inner two poles. By interpreting these two bar magnets in the elementar magnet picture, combining them leads to a new larger bar magnet with one north- and one southpole. Now the field lines that originally were in opposite direction seem to be going in the same direction as for the outer two poles. Why did they flip? What's happening here?