Saving an image is very high quality. But so is DVR. Usually a DVR copy is perfect.
DVR sounds like a very good analogy to me. The website is showing you something, and you make a personal capture that you can replay at any time. It was distributed to you specifically, and you're time-shifting it. You're not taking a personal copy held by one person and making it two personal copies held by two people, which is what happens when you rip someone else's DVD. And the same way, you shouldn't take that image you saved and start distributing it around.
DVR sounds like a very good analogy to me. The website is showing you something, and you make a personal capture that you can replay at any time. It was distributed to you specifically, and you're time-shifting it. You're not taking a personal copy held by one person and making it two personal copies held by two people, which is what happens when you rip someone else's DVD. And the same way, you shouldn't take that image you saved and start distributing it around.