The view of a more or less revealed woman's breasts from above or the side.
Recently, there have been almost exclusively bikini pics posted. Well, there is a bikini group for that.
There are so many ways to describe the "glory hole" ...and so many options to explore it. You can lick it, finger it, stretch it or just adore it. Maybe slide a tongue into it, then a finger or two, and then the whole fist. Once its good and stretched you can suck on the edges of the gaping treat.