1950s gigi young dress/ strange hem

Hello so i have a gigi young dress..which needs tlc ...but it has the strangest really long sheer overlay. I found the same dress on pintrest almost exact im sure of it( except mine is missing the bows )and it did not have this extremely long hem.

My question is is this normal or was this made this way oringally..or did the hem detach. And it wasnt resewn??

I Cannot find any hole or stitching where the hem would of been sewn on oringally. Nothing not a trace. Its almost as if it was not ever made the same length as the under lining.

So in my searches i found no other dresses that have this look....so do i need to fix this? Or is it supposed to be this way?

 

These late 1950s chiffon dresses often have very deep hems, perhaps it was washed and something either shrunk or grew so the hem was unpicked to redo it.