Above the Colors: ON/OFF widget is Export All Widget (dashExportOpt) to export every note in your TBX (whose $HTMLDontExport is not true).

Normally, only certain notes are exported:

•  Special notes—BlogTopNote, Blog Pages, blogAboutNote, Archives, Categories.
• Notes inside Blog POSTS and Blog PAGES container notes whose $blogReady has been set to true.
• Sub-posts using the OWNPAGE and FOOTNOTE export options.

All other notes are skipped, including all sub-posts and sub-pages of COMPILED pages—and of course those with the SKIP export option.

Skipped notes will not export and also will not appear in the Preview Pane.

When you check the Export All widget, all notes get exported, and so all notes are viewable in the Preview Pane.

You will use this button frequently because activating Export All is the only way to view notes that do not export as their own webpage.