A few thoughts:

1. Since this is something shared across views ideally (within PDF textbooks, Files & Uploads later, and now Settings), this should really be within the sass/elements/ directory.
2. Also, in Sass files we use a 2-space tab indent for code (versus the 4 within JS).
3. I'd prefer if the body class used to call this functionality was named "feature-upload" (we don't have a lot of body classes focused on features, but I can see this convention being used in the future).

Mind moving this and converting the tabs?