How would you explain this phrase?
The narrow bathroom runs alongside Lev’s study and bedroom under a tin shed roof, added on the house some time between Porfirio Diaz and modern plumbing. Its fixtures stand in a row like soldiers at attention: the bathtub on clawed feet, the lavatory on its pedestal, the cabinet with Lev’s medicines and everyone’s shaving things in a jumble. The pitcher and bowl on a stand. The dreadful hairy rug someone should throw out. Lev should write a paper: “The Political Challenge of a Commonly Held Bathroom: No One Has the Authority to Throw Out the Rug.” And at the end, the captain of this army: the commode. Its tank above, the pull chain awaiting the private’s salute.

How would you explain this phrase: between Porfirio Diaz and modern plumbing?
Thanks!
PS: It’s from The Lacuna by Kingsolver.

Question

How would you explain this phrase?
The narrow bathroom runs alongside Lev’s study and bedroom under a tin shed roof, added on the house some time between Porfirio Diaz and modern plumbing. Its fixtures stand in a row like soldiers at attention: the bathtub on clawed feet, the lavatory on its pedestal, the cabinet with Lev’s medicines and everyone’s shaving things in a jumble. The pitcher and bowl on a stand. The dreadful hairy rug someone should throw out. Lev should write a paper: “The Political Challenge of a Commonly Held Bathroom: No One Has the Authority to Throw Out the Rug.” And at the end, the captain of this army: the commode. Its tank above, the pull chain awaiting the private’s salute.

How would you explain this phrase: between Porfirio Diaz and modern plumbing?
Thanks!
PS: It’s from The Lacuna by Kingsolver.

Answer

This describes the antiquated nature of the bathroom, added at some time in the early years of the 20th century - after Diaz's presidency, but before the advent of 'modern plumbing'. This suggests that the facilities are rather basic.

Answer

All this means is that the time referred to is a long time ago, sometime between 1900 (when Porfirio Diaz was president of Mexico) and today.  He then goes on to describe some of the old features no longer common in today's bathrooms.  For example, the toilet has a chain hanging down used to flush instead of a small lever.