A position where the leader and follower are looking into the same direction and are on the same count. It is common for the follower to be in front (for moves like Body Roll), but the leader can also be in front after a Tap Turn.
Because the leader and follower are on the same count, you cannot do a regular Turn to return. Somebody needs to “skip” a count somewhere, so a Tap Turn is logical. This is always done by the leader.