When I use the “Text post with attached link” option with a link attachment type of “Attach your blogpost” a thumbnail from my Nextgen gallery is included in the attachment. It seems to be the last image uploaded to a Nextgen gallery. How can I control what thumbnail is used in the attachment?
Plugin will take featured image from the post. if there is no featured image it will take the first image from the post body. if your post body has no images it will take the specified default image.
There is also a possibility to specify featured image from the custom meta field.