Of course there are for almost everything (even for image settings) standards that have been established by any organizations or manufacturers.
However, these standards give it just because certain people have decided how it should look (for as many people as “good”) and so other manufacturers can follow.
Take, for example USB. USB was and is certainly not the only and best standard, but it is a standard to which other manufacturers can follow.
Because this standard is not perfect but it is always evolving every few years is the standard changed or extended.
And a standard such as low-resolution images are displayed on a much higher screen also does not exist, at least I know of no such standard.
And even if there were such a standard would be in this certainly not described the great parts of the image are missing.
I not known any system that the image calculated as 6:5 so that automatically missing several picture lines with picture content.
It would also be pretty stupid of the programmers that fight for every bit of computing power to calculate as many lines, you can not see at the end anyway …
So you cut too much from the image.
What is overscan, why and how this is defined and what this has to do with resolution, you can read on Wiki.
In order to respond to your example with your grandma and the lines in the image.
(I wanted to really no longer respond to your posts, but that’s pretty much the first post of you in which you will objectively remain in this discussion. In my review I’ve imitated the way you express yourself, … and as you can see You do not like it ;-))
So I understand Your statement that a picture in which some stroke are very clear to see, but spoil the image in any case, is better for all people, as the same picture, in which these lines but can not be seen ..?
Of course the picture in which you can’t see these Lines looks better.
Especially for your grandmother. And for your grandmother, it is the personal impression why the picture looks better because she can see the picture but can not see the disturbing lines.
It’s a personal impression.