I see. An explanation is below:

large view only: This permission only applies to photos. It means the "share-to" users can view large preview size images (600x600), but not the original images if the original resolution is higher.

original view only: This means read-only.

view comment & rate: This means read-only to the files and comments & ratings.

comment and rate: This means read-only to the file, plus comment & rate to the file.

upload/add: Upload more files into the folder;

full access: Add/Edit/Delete/Comment & Rate. All access.