Adding an asset preview to a custom metadata editor
How to add an asset preview to a custom metadata editor.
Adding an asset preview
To add an asset preview to the custom editor, select Editor Items in the list of elements in the left part of the window.
Select Other graphical items from the drop-down list below (the one that usually says Show all items).
Now the list of available items contains a File preview that you can drag into your layout and place and size as you prefer.