To create a Metadata item, in the Browser click on 
on the right of the screen
The following windows opens :
Enter all the informations and click on 
.
The item is created in the database with the icon 
.
IMPORTANT: These items created in the database will be used as "ORGINAL".
That is, whenever an original item is added in a playlist or a playlist is generated using an original, a copy will be created in the database but without an icon in the browser.
Once the item is created, it can be added to a screen.
To do so, open the show, then drag and drop the item on a screen.
From now on, all palylists generated from this template will have the item linked to this screen.