Windows cursors are multi-layered
(Starting with Windows 7)
In other words one pointer file, let's say the standard right arrow
contains multiple images each showing at different DPI settings.
A user running at 144 DPI (150%) would see a different / more detailed arrow pointer that a user at 96 DPI (100%) but both arrows would appear to have (almost) the same size on the respective user monitors.
Cursor resolution sizes on specific DPI settings
Mouse cursor specs between Windows versions
|DPI scale (%)
||Optimal cursor size (px)
*static (cur) goes up to 128px, animated (ani) goes up to 64px
Size of files also increases significantly as larger images get included in mouse pointer to make them compatible with higher DPI screens.
Using a (older) cursor pack lacking higher DPI layers on a high DPI screen will result in a blurred and less-detailed pointer being shown (the small bitmap layer will get scaled up).