My guess, Cut Scene Playback

I can see them working it into the story.....

<Re'gistal Maloor> "I will teach you how to use the power of the Echo to replay past Echoes."
<Holy Omen> "Let's do it."
<Re'gistal Maloor> "But this lesson will come at a cost, 1,000 gil per replay, what say you?"
<Holy Omen> "You serious?"