It could be unique because it allows fans to explore uncharted territories of Spider - Man's origin. Maybe it focuses on a side character's view of Spider - Man's first year, like a bystander or a minor villain, which gives a fresh perspective.
Often, fanfiction like 'Spider Man Year One' is unique as it can combine different elements from various versions of Spider - Man. It might take the best parts of the comic books, the movies, and even other fan - made ideas to create a completely new and exciting take on Spider - Man's first year as a hero.
The uniqueness of 'Spider Man Year One Fanfiction' might lie in the freedom of the writer. They can deviate from the canon. For instance, they could give Spider - Man a different suit design in his first year.