I rarely set foot in a supermarket in the 60's and early 70's, as my dad worked in the grocery store owned by his uncle. Occasionally I would go in the local Kroger with a friend, or in Thriftway when at the shopping center in Cincinnati. They were much bigger than any of the other stores in my town. Uncle Fred's store had three aisles, and the sales area measured about 28' x 60', with a couple back rooms for the office, motor and compressor room, and walk in cooler. The meat department was in the back of the main room. There was also a very small restroom. The total square footage would have been about 2200. There were two registers, buy the second was used only around holidays, or if the main one was out of order. The wholesale grocery truck came once a week, and overstock was kept upstairs (a conveyor system was installed about 6 years before the store closed in 1974).
I found the article to have somewhat of a "big city" slant to it. Much of what it mentioned would have been more likely to have been found in large cities. I agree most of the shoppers were women, but men, especially older, weren't uncommon. A few women came in all dressed up, if they stopped in on their way home from an office or similar job. However, most visited in a housedress or pants (including jeans), especially if they lived on a farm. Most of the customers were white, which would be expected in an area that had a 95% population of that demographic. There were several black customers who shopped there frequently, though. Everyone was treated as a valued customer regardless. Meat WAS a big deal, and his was known far and wide for exceptional quality, Hams were Kahn's, and all beef was local farm sourced. Turkeys were from a farm about 20 miles away, and eggs from about 4 miles distant. As for produce, most apples came from an orchard about 5 miles away, with their fresh cider and candy apples in the Fall. Sweet corn in the Summer was grown on local farms, along with some other in-season items. Other produce came from a distributor in Cincinnati. The frozen section was small, as many customers had gardens, and froze or canned their own food. The majority of the merchandise was canned or packaged food, and some cleaning items, and personal hygiene (toothpaste, shampoo, etc.) Check out did take a little longer, but most orders weren't huge. And of course, many of the customers would have a short visit with the cashier, as most customers knew the employees.