This isn’t a record cover, as one might suspect. it’s rather a sleeve holding three reels with a total of 21 three dimension pictures of the Canary Islands, to be viewed in the View-Master. From Wikipedia:
View-Master is the trademark name of a line of special-format stereoscopes and corresponding View-Master “reels”, which are thin cardboard disks containing seven Stereoscopic 3-D pairs of small transparent color photographs on film. It was originally manufactured and sold by Sawyer’s.
The View-Master system was introduced in 1939, four years after the advent of Kodachrome color film made the use of small, high-quality photographic color images practical. Tourist attraction and travel views predominated in View-Master’s early lists of reels, most of which were meant to be of interest to users of all ages. Most current View-Master reels are intended for children.