Selecting the "View Reader Experience" tab on the right side of the screen of a teacher or librarian's administrative view will take you to that account's view as a participant. It does not mean you can see the view of the reader/student whose page you have pulled up to view. Rather, it is your own account's view as a reader.
Likewise, if you are in the reader experience, you can switch back to the administrative side of your site by selecting the "View Admin Experience" tab on the right side of your screen or by clicking the gear icon in the upper right corner of your screen and selecting Admin Access.