Here is a sentence from Dickens:
On somebody’s motion, we resolved to go downstairs to the dress-boxes, where the ladies were.
This is a scene in a theatre, when drunk Copperfield with friends goes to some specific part of the building where ladies were. But I can't find anywhere a definition of the word "dress-boxes", nor its picture.
It was translated into Russian as a "theatre box"(ложа, loža) in the Russian translation of the book. This makes sense, but why "dress"?