Yes the high def TV screens have about the same resolution as computer monitors. What I was referring to is the fact that the Hirise images are so large that you can only view a small portion of them at a time when viewed at their highest resolution.
But then to search for specific features you do want to view them at their highest resolution. As it is now, with a standard size computer monitor, you have to spend a significant amount of time just scrolling through the image to scan the entire image.
In that image I cited, I was looking for small features that might indicate quite recent (like yesterday) water flow, such as small channels, etc. It would be very convenient to be able to see the entire image all at once at its highest resolution in order to do this search.
Here's another interesting one:

HiRISE | Solis Planum Valles (PSP_002156_1415)
http://hirise.lpl.arizona.edu/PSP_002156_1415

Is the white material that so often appears at the tops of the elevated portions in the image frost or evaporites?

Bob Clark