Particularly with Safari which has some interesting bugs in the last two sets of use cases.
Tests below are for Safari 11.4 on BigSur 14.1.1, and iOS 14.6, Safari 14.1.
Apparently Catalina has more issues.
External src, alt
External src, alt, role="img"
External src, aria-label
External src, aria-label, role="img"
Inline data src, alt
Inline data src, alt, role="img"
Inline data src, aria-label
Inline data src, aria-label, role="img"
External src with title, alt (announced as Group in MacOS and not display in image rotor, ignored in iOS)
External src with title, alt, role="img"
External src with title, aria-label (announced as Group in MacOS and not displayed in image rotor, ignored in iOS)
External src with title, aria-label, role="img"
Inline data src with title, alt (announced as Group in MacOS and not displayed in image rotor, ignored in iOS)
Inline data src with title, alt, role="img"
Inline data src with title, aria-label (announced as Group in MacOS and not displayed in image rotor, ignored in iOS)
Inline data src with title, aria-label, role="img"