After choosing the Forum List (Above Nodes) widget position (or Forum Overview Top), in order for content to show in the widget you need to edit the thread and mark as featured. If there is an image in the OP that will show
After choosing the Forum List widget position, in order for content to show you need to edit the thread and mark as featured in order for them to display in the widget.
One thing not totally clear, when you feature click on Custom to get meow options, (EDIT that should be more options, not meow options) e.g. change title, assign a different image to the one in the post.