Decorative graphics is prime example use case in WAI-ARIA docs for the presentation role. Its purpose is to remove the element from the accessibility tree. By

Decorative graphics is prime example use case in WAI-ARIA docs for the presentation role. Its purpose is to remove the element from the accessibility tree. By comparison, alt="" is much less direct and obvious. I consider it an unfortunate historical quirk that it is not the same as a nonexistent alt attribute. For decorative images I recommend using presentation role to make the intention clear.