This window is also called the Zotero Preview Pane, Zotero CSL Preview, or cslpreview.xul.

The Zotero Style Preview is a tool to preview CSL styles. It can be opened using the “Style Preview” button at the bottom of the Cite pane of the Zotero preferences.

The Style Preview window shows rendered citations and bibliographic entries for all installed CSL styles, using items selected in your local copy of Zotero.

You can filter installed styles based on their formatting class (e.g., author-date or numeric), as well as modify the language of formatted citations and bibliographies.