What makes the 'I Can Only Imagine' story by Amy Grant unique is that it has the ability to create a vivid mental image in the listener's mind. The song takes you on a journey of the imagination into the realm of the divine. It's not just about the words or the music, but the overall feeling it imparts. It has a timeless quality that has allowed it to remain relevant over the years, and it has been able to reach people across different generations and cultures, which is quite remarkable in the world of music.
One unique aspect of the story is its simplicity in expressing a very profound concept. It doesn't use overly complex language yet it manages to convey the grandeur of the afterlife.