You can hide irrelevant publications when switching from public to confidential by clicking on the icon in the top right corner.
As default all public publications will be shown. These are all the publications that were set to "public" on admin without the ones that were set to "private".
When you want to see both public as private (confidential) publications, you need to click on the private icon. All publications set to confidentials on admin will be shown here together with the ones that are public.
The kiosk manager can set every publication to confidential or public. Find out how.