The playlist can be used as a media pool.
There are several ways to add clips to the playlist.
Use file > open file or CTRL-O, navigate to the folder containing videos/images select the media to open, use Shift and Ctrl to select multiple items. The selected items will open in the playlist.
Another way to add clips/images to the playlist is to drag and drop from the file manager on the playlist panel. Multiple items can be selected.
If you select one image or clip and drop it on the source viewer it will play in the viewer. It can be added to the playlist using the + icon or Shift + a. If multiple items are dragged and dropped on the source viewer the items will be added to the playlist.
The playlist is versatile. It has many uses.