This seems like a good place to make a request:
If you store thumbnails/screencaps on Stoorage, it would be very helpful if they were in portrait mode (instead of landscape). That is, more vertical than horizontal, better approximating the page dimensions.
The limiting magnification factor is the site's maximum width, which means that a lot of space on the page is wasted when the width of the screen is taken up by a landscape format, but only a third of the vertical space is actually used.