When should a leader use "language from the center" and when should he or she use "language from the edge"?
Since your previous question referred to the article in the link below, I assume that this one does as well. The article in the link says that leadership languages come in two basic sorts. There is the sort that leads from the center and the sort that leads from the edge.
Leading from the center involves the sorts of behaviors and language that were once seen as the only way to lead. A person who leads from the center tries to dominate the organization. They are in the middle of every decision. They convey their opinions and attitudes to others and they expect that others will follow them. They do not really tolerate dissent. This sort of leadership can be important in situations that are quite urgent. In an emergency, there is little time to build consensus. Instead, a leader must use language from the center and really push people in a given direction.
Leading from the edge is less coercive. This leader still leads, but they do so more by facilitating than by coercing. These leaders listen to everyone and try to make sure everyone is on the same page. They try to help people understand which way to go rather than to force them to go in a given direction. This sort of leadership is more appropriate in less stressful situations.
There are, then, times and places when each of these languages is more appropriate. A good leader, the article says, can use either language as the situation requires.