So... I think you're assuming that the order precedence to how the folder formats are applied would follow these sort of rules:
- custom (default) = details view
- content type = thumbnails
- folder specific format = thumbnails inherited from content type format, since no explicit view-mode is specified in the folder specific format (i.e. it's unchecked)
But I don't think that's the way things work... When you create a specific folder format I think Opus is only applying format items 1 and 3 above (although "technically" - item 1 is coming from whatever the default format is as defined in the default or saved "layout" Opus is loading when you open the lister, as oposed to the actual "custom" format - the two of which are likely the "same" for many users)... and you're going to need to check that display tab "View" box to enable thumbnails view-mode for the folder format. Case in point - even though you're seeing "details" view mode unlike you expected, I'm assuming Opus is in fact still reversing the sort order such as you have specified in the folder format for "Window Clippings" - yeah?
Leo's venerable "HOW TO: Understand and Configure Folder Formats" FAQ has this to say to explain the behavior you're observing:
[quote="Leo"]Opus will go through the list from top to bottom until it finds one which can be applied to the folder you are viewing.
If a format has been explicitly saved for a particular directory then that format will be used for that directory, because those formats are at the top of the list.
If the directory doesn't have a format saved explicitly for it then Opus next checks the Content Type formats.[/quote]