@aartaka
Nothing public yet. The essential idea is that participants can "pull" a card off the board and it becomes unavailable for anyone else. And if you're sharing your screen (no idea how to do that.) then you can't pull a card or edit. Possibly only just view the card title.
Because pulling an index card and 12 people moving over to their desk to watch them write on it with a pen sounds insane but we metaphorically do that with Jira et al so often.