[samjanis]

Gotcha. Turns out to be Chrome (or Chromium) specific.

In article.js loaded with this page there is a section that looks like:

dataLayer.push({event:"mittr:detectIncognitoMode",action:"detect",category:"incognito-mode",label:n})

Commenting out the function block surrounding it where it starts with "function y() {..." stops the class ".incognito-wall-shown" from being applied to "section.incognito-wall" found in the main HTML page - although this is just a quick dig and haven't debugged any further (I'm halfway through something else but this caught my interest ;) )