1How to craft it
Work Benchwhat it does in a server
Multiplayer only, and narrower than it first sounds. Each use jumps your camera to the next player in line, so on a busy world you cycle through everybody rather than picking who you want to watch.
The real payoff is map data. Anything the person you are watching has uncovered fills in on your own minimap, so tailing a friend through a fresh cavern system explores it for both of you. On a new world that saves a lot of duplicated walking.
where it does nothing
Alone in a world it just tells you off and stops there. It also cannot reach the other player in local splitscreen, so a couch session gets nothing out of it.