We can think this analysing the graph,
H represent magnetizing field. So on right side where the solenoid has magnetizing substance would require less magnetizing field .
why ? That's because $\mu $ would be more.
And as from the equation given by you $H=B/\mu $
H should be less for right side.
And it should be more on left side. This can be seen as intercepts of y axis in graph 2 only.