Once upon a time, color slides were a mainstay of home media - no family gathering was complete without a vacation slideshow, they were used to document milestones from weddings to graduations, and yes... many red-blooded males of the era collected slides of young ladies in various states of undress. These were both shown at stag parties and - time & privacy permitting - for personal use.
They distinctly capture a certain time and place and feel, partly due to the unmistakable color palette of Kodachrome slide film. Subtle but with rich hues, muted but with plenty of depth. The settings (often in various California locales) were evocative, composition was pretty good, and of course the ladies were lovely - buxom and/or statuesque, classical beauty and/or girl-next-door cute, elegant and/or campy. A lush pair of breasts was back in fashion after the more boyish flapper-esque figures of the 1920s and 1930s, and that feature is certainly emphasized in these images (and they've never since gone out of style).