Until now, a board belonged to one team. If another team needed the same picture, the only option was to copy it. From that moment, the two copies started to drift apart.
Here is how that usually plays out. A production team and a quality team both follow the same scrap rate. The production team updates its board every morning. The quality team updates its copy once a week, when someone remembers. After a month, the two boards show different numbers. The next joint meeting starts with a discussion about which number is right, instead of what to do about the scrap.
The problem is not discipline. Two copies of the same data will always drift, because every update has to happen twice.
A mirrored board is one board shown in several teams. It is not a copy. The data lives in one place, so every team that sees the board sees the same numbers at the same time.
This matters most where work passes between teams. In an end-to-end flow, delays and misunderstandings often start at the handovers. When both sides of a handover look at the same board, they can discuss the flow instead of their own version of it.
The board header shows how many teams the board is mirrored to, for example Mirrored to 2 teams. Click it to see every team and what each team can do. To change access or add teams, open Mirror settings.
A team that receives a mirrored board can always see where it comes from. The header shows Mirrored from and the name of the team that owns the board. Click it to open the original board.
If a team has view-only access, its header also shows a View only label. That way, nobody has to wonder why they cannot change a number.
A mirrored team can remove the board from its own view at any time. This does not affect the owning team or any other team.
Deleting the original board is different. If the owning team deletes it, the board disappears for every team it is mirrored to.
A mirrored board helps when:
Use view-only access when a team needs the picture but should not change it. Use edit access when both teams own the numbers together.
Start by looking at your current boards. Which numbers do you keep in more than one place? Those are the first boards to mirror.