Terada: We were exploring different ways to play the game in parallel. In one way, Link could copy and paste various objects, such as doors and chandeliers, to create original dungeons. During this exploration phase, this idea was called “edit dungeon” because players could create their own gameplay of The Legend of Zelda.
Aonuma: They showed it to me and told me to try it out. As I played, I started to think that while it's fun to create your own dungeon and let other people play it, it's also not so bad to place copy-pasted items on the playing field and create gameplay where they can be used to fight enemies. That was the beginning of “echo” gameplay. The gameplay went from creating dungeons up until then to using copied-pasted items as tools to advance your own adventure.