Michelle Rodriguez - Yes, you can cover the label while you are decanting the bottle. The idea with decanting, especially old wines, is not to move the bottle from its original position. Grabbing the bottle overhand to decant is the only real way to have control over the angle and speed at which you pour, ensuring that you are not disturbing sediment. You are doing this in one single movement in front of the guest. Also, since you have already presented the bottle to the table in its cradle, the guests know what you are pouring. But notice he puts the bottle on the table with the label facing the guests again before he begins to pour the decanter around the table.
There are always small exceptions to the big rules- such as twisting a bottle of champagne around while opening it, etc.