The derailleur hanger appears to be installed correctly.
Notice there is a small bolt forward of the axle, that obviously goes in a hole in the dropout and stops the hanger falling off when the wheel is out.
The hanger also aligns with the dropout slot to allow the wheel to be removed.
I think your confusion comes from the fact that hangers on more modern bikes tend to have the lug where the derailleur mounting hole is located behind the axle, but these bikes also have downward facing dropout slots rather than rearward facing ones.