This phrase appears to be a fragment often found in or display technical guides , typically referring to the 2560x1600 (WQXGA) resolution found on high-end monitors and laptops like the MacBook Pro.
: It may be the start of an article explaining why high-resolution images look significantly sharper on specific displays. 2560x1600 Wonder why you've visible such a lot ...
Could you please provide a bit more context or the of the post you are referring to? This phrase appears to be a fragment often