How does this power outlet configuration in my new home work?
I've seen installations like this before, and I think you're missing a piece of the puzzle.   

First step, is to get that cord out of the wall. 

In a typical instsllation, the male receptacle at the bottom of the wall is connected to the upper receptacle via NM cable (or other approved wiring method).   The male end of a cord (like the one in the wall in your case) plugs into a nearby receptacle, while the female end plugs into the male receptacle (like the one in your photo).  This cord passes power to the upper receptacle, via the NM cable within the wall.

I'm not sure if this is how your setup is wired, since you say the receptacles are connected to the mains.  But this is how a typical Installation works.

You should be able to verify this with a multimeter (when you have access to one). With nothing connected, neither of the receptacles should have power.   You should also be able to get continuity between the receptacles. 

Plugging the cord in as described above, should supply power to the upper receptacle.