The book itself came out at an interesting time - just after WWII. Before World War II, it was far more common for even middle class people in the US to have servants - especially maids and cooks. Magazines would have recipes for "cook's night out" or articles about coping when a servant quit before a big party. It was basically assumed that if you could afford a cook, you had one, or if you did your own cooking, you had help serving and cleaning.
But the war changed things, and servants were harder to come by, because no one wanted to be one. This is why prewar apartments in Manhattan, even middle class ones that a school teacher could afford, had maid's rooms, but postwar ones don't.
This cook book, therefore, is how to entertain when you don't have a servant. Which explains the title - instead of staying in the ktichen, the cook is also the hostess and must be there to entertain her guests. It's also a tiny bit about cooking on a budget and there's even a chapter on emergencies - what to do if your guests arrive on the wrong night. This seemed to be artful combining of canned soups, vegetables, fruits and meats (including, of all things, canned ground beef) with staples like rice or noodles and a bit of wine to create a meal.
The recipes themselves are...not useful unless you're an accomplished cook who knows how to judge quantities because she doesn't say how many each dish serves. I don't mind recipes in paragraph form, although I do prefer the list of ingredient types, but these are harder to follow than most. They're presented as menus, which can be useful, and various ways - Sunday brunch, Sunday supper, buffet, husband cooks (yeah, a separate chapter, and the recipes include "wash the greens and prepare the dressing for him to shake up." and "since men eat the fruit anyway, consider your fruit arrangement to be dessert as well as centerpiec" - which is actually a good idea, and one my mother-in-law applies for Thanksgiving to good effect.)
And the book is primarily about entertaining - how to set up a buffet table or little tray tables, for example, or how to be really well organized. Her recipes do include "make this day before" or "make in the morning" which is also helpful. But she also says that you need one maid for every four people for a formal dinner. She tells the story of her first Thanksgiving, when her maid quit. She'd made the entire meal, turkey and all, ahead of time, so things only needed to be reheated, but she drafted the guests of honor (all male) to be butlers when they arrived. Which is cute and amusing and they enjoyed themselves, but...I don't know.
And a lot of the recipes are not to my taste - heavy and sweet and even her formal dinners use canned fruit and molded salads/desserts. But such were the fashions of the times and often that would be the best way to get fruit.
On the other hand, there was another sign of how times have changed - she said how she made a "mock" chicken stew with chicken broth, veal, vegetables and dumplings made with chicken fat, and then she gave a recipe for lamb shanks that would have all her guests believe they were turkey legs.
It's hard to imagine a time when veal and lamb were the cheap meats and chicken and turkey were the luxuries.