iOS Share vs. Action Icons
I suspect that 90% of users have no idea what distinguishes these two (completely separate) rows of icons, aside from the color.
(To be clear, I have no idea either. Theoretically, it’s “share” and “action”, but those concepts are so muddy that it’s hard to know which group a particular app extension belongs to.)
Further confusing things is that the “More” button in both rows brings up a panel titled “Activities.”
That's something I wondered too. What the heck is the difference?