I realized that my reading entirely too many vintage sewing books made me categorize the dress as a "wash dress".
When I first came across the term wash dress I had mistakenly thought it was a dress one wore to do laundry. As I saw the term more often I came to realize that a wash dress is one that washes easily and can be ironed simply. A dress with no tricky parts to iron in those pre-spandex days was called a wash dress. Again and again I found dress drafts for dresses and night gowns that were praised for how easy they were to iron. The blue dress in the photo above is a wash dress because once you remove the belt you can just lay it flat and iron it is under five minutes.
There are other dress categories that no longer exist.
This is a dress that you might wear to a dressed up event in the afternoon. Often they were sheer dresses worn over solid colored full slips. Afternoon dresses are sort of similar to today's cocktail dresses. You saw this term from the 1930's though the early 1960's. An afternoon dress is a later iteration of the tea dress worn by a woman as she served tea to her visitors.The dresses were developed in the 1700's so women could have a few hours freed from their corsets. The dresses were meant to be worn loose, uncorseted but still proper enough to wear with company around.
In the early part of the last century one did the hard physical labor of running a household, laundry, washing the floor and the like in the early part of the day.After you did the gross and sweaty work, you would change your dress and put on a nicer dress to sit on the porch and either visit with friends as they passed by or do things like peel vegetables as you sat on your porch. You could look presentable and visit. Porch dresses were in particular made for young women of marriageable age.I have seen this term used mostly in the 1920's and 30's.
Clearly this term is found only in the 1950's and 60's the great patio era. A patio dress might be a cotton halter dress with a bandanna print, something a bit festive but still casual. It's the dress one might wear to host a casual back yard party.
Our lives are simpler now in many ways. Advancement in textile technology means that lycra and knitwear make ironing less of an issue. I am one of the few people I know who irons regularly Advances in washing machines mean that getting a "good" dress dirty is less of an issue than it was in the past. many of the rules about what is appropriate to wear at which moment of the day have relaxed as well.
This is the evening version of a tea gown. It was a dress meant to be worn sans girdle by a woman giving a dinner party.These seemed to have developed during WWII when servants were harder for middle class and upper middle class families to hire. If your hostess was also cooking and serving the meal, it made it easier to be a charming hostess if she had a bit of freedom of movement as she served. Some of these dresses were bathrobe /evening gown hybrids, some tended to pull from he language of "exotic' clothing like kimonos and kaftans, some played off of the language of glam pajamas.
But here I am, typing this post as I wear a wash dress, a sibling of the dress pictures above.