Ah, that explains a lot. I do heavy ad and tracker blocking, including blocking loading of all web fonts. I constantly find various arrows and other tiny images not rendering and didn't know why. You'd think for something like a left and right arrow, you could at least set the alt text to the unicode character for left or right arrow, or at least ASCII art (i.e. "->" and "<-"). It would also make it make sense for people using screen readers.