The indication shadow is the same as that of the normal shadow badminton routine. Here the only difference is a indicator(person) will be standing in front of the middle of the net and will be indicating you to move in a particular direction.
The major advantage of doing this indication shadow is that, you more likely feel a actual game situation scenerio since your opponent will take full control of your movement rather than you moving inside the court based on your own instinct.
The indicator (person) should have prior experience in this routine and must time the direction correctly after the person doing the shadow badminton should be able to move in his next direction after he comes to the center court.
This drill can be made tough by adding more speed sequences and also by adding more repetitions.