You can find the preview pane of the Trash can main tab on the right side of the application window.

If the displayed content is long or wide, use the vertical and horizontal scroll bar to display the desired portion of the content.

The preview is not zoomable.

All previews (by main tab)

Articles, Collections, Contacts, Editions, Pages, Planning, Publishing, Start, Tracking, Trash can

For general information see also

Preview