This event has led to the sincere recognition by the Lamanites that Christ is worthy of worship. They have had their indication of the efficacy of that worship when the cloud disappeared. Now they find themselves in another divine-evidenced event. They are surrounded by a pillar of fire. Now they are inside that same fire that they saw around Nephi and Lehi.
Visually, they can see that they have moved, but moved spiritually. They were outside of the protective divine fire, and now they are inside of it.