Sometimes they further optimize it for a goal, or maximize it to have everything. Sometimes organize it, provide additional material that fans might appreciate, add commentary. Port it to a platform where previously it was inaccessible.
For examples, an artist's discography is sometimes neatly organized in folders, by year, and the files are tagged with metadata. In case of anime, fans improve or outright provide subtitles. They often do extra things like including karaoke for the opening and ending, color coding subtitle lines to match the speaker's personality or design, and provide stylized subtitles for signs and other letterings on the screen. In case of movies, they are often optimized to a specific kind of usage, for example to be able to be viewed on every phone, or to have a minimal file size. Sometimes, especially older releases, are digitally cleaned up and enhanced. Games install easily and is packaged in a way that it just works, without faffing about with the launchers and things like that.
For examples, an artist's discography is sometimes neatly organized in folders, by year, and the files are tagged with metadata. In case of anime, fans improve or outright provide subtitles. They often do extra things like including karaoke for the opening and ending, color coding subtitle lines to match the speaker's personality or design, and provide stylized subtitles for signs and other letterings on the screen. In case of movies, they are often optimized to a specific kind of usage, for example to be able to be viewed on every phone, or to have a minimal file size. Sometimes, especially older releases, are digitally cleaned up and enhanced. Games install easily and is packaged in a way that it just works, without faffing about with the launchers and things like that.