With this feature you can blur out certain pages so they aren't readable. This is mostly used in combination with the PROKiosk plan. This way only readers that have certain access tags can read the whole magazine. Read more about the PROKiosk plan here
First go to the settings of the magazine you want to edit
Scroll to the "Visibility Settings" and check the box at "Blurred magazine" and define what pages should be blurred out. You can select single pages ("1"), whole areas ("3-7"), or open areas ("20-"). If you want to make more than one selection, use a comma as a divider ("1, 3-7, 20-").
You can also overlay an image on top of the blur to get your readers to click a link. This is done with the "Page teaser". Learn here how to add one.