What does a "low quality" page look like.

With fee account it says pages are "low quality."  What does a "low quality" page look like compared to a high quality one?  I assume this relates to the image resolution?

Yes low res does refer to the resolution. A low res picture simply looks more pixelated. Free users will have images compressed if the webpage is large. If you are saving a webpage with many pictures chances are the resolution may drop.