Accepting or declining quests or texts that are being picked up by your teammate.
The situation is similar when it comes to accepting quests and reading texts from books or notes placed in the game world, so:
Your friend takes a quest from an NPC or reads a note → while you’re in the game, a message pops up on your screen asking if you want to accept the quest, or mark the note as read (e.g. PageUp) — so you can read it now with a hotkey (e.g. F4) or later in the journal (J) — or decline it (e.g. PageDown), which would mean you’d have to go to the note’s or NPC’s location yourself and read the note or take the quest manually.
Right now everything is taken automatically, and if I’m doing something else while the other player picks up a quest, I miss all the information the NPC says. And when they read a note in the world, I miss the location where it was found, which matters to me. We play together, but it shouldn’t feel like we have to run around holding hands — yet that’s exactly how it works at the moment.