She really does have great breasts, especially for a more "mature" woman (very difficult to tell with Japanese, as they seem to age slowly). In the shorter (~3 minute) version of this video, you really only get to see them when she's fully bent over, in doggy style. Here, they're pointy and swinging out to opposite sides, which not everybody likes (though I do). In this full version, you see her (briefly) oriented upright, for cowgirl, and her breasts seem fuller and rounder. It's remarkable how much a breast can seem to change shape and size, just down to the angle a woman is holding her torso.
This is a brilliant quality amateur video that really delivers! There's a shorter (1/2 length) version of this video, on this site, that is mislabelled ("hand job"). The extra time in this one is NOT a waste. THIS is the superior version. The woman seems a little bit dopey. I suspect she's drunk, and that is what helped her get the courage to do the video.