What happened to my desktop icons?

I just got my first Windows 11 computer, and after spending a few days setting it up to the way I like it, I woke up one day and noticed that some of my desktop icons look puny now. Example:

Unless I'm losing my marbles, I could've sworn that the Notepad2 icon was as big as the other two icons before -- why/how did it suddenly become so small? I've tried deleting all the icon caches and the issue remains. Since this is happening with older programs like Notepad2, I'm guess it's because they lack the larger icon sizes in their EXE file, but the question remains: how was Windows able to show the icons the same size as the others before? I'm 99.99% sure I have never seen these square borders around any of the desktop icons before because they are so off-putting I would've noticed it