If you have enabled the Simplified view for web pages, you might see a message like this:
If you choose a simplified page view, Adblock Browser will open a new tab in “reader mode”. The browser will format the spacing and remove some images and colors making it easier to read. It will then look like this:
This option is not enabled by default. To activate it (or deactivate it), go to Settings > Accessibility > Simplified view for web pages.