Where to get more background images for Android Wear the faces of watches?

I use the face of watches Portions of Looks. When entering the dial parameters, one of the elements is "Background". Choosing it reveals:

  • "Empty"
  • "Common" (two elements) with a Porter OS icon
    • "Works of art"
    • "Playing"

By choosing "Artworks", you get an abstract background, dynamically changing, with different shades.

Is there a way to add / download more background apps (?) To add to this list, or other "works" to choose from?

(Note: The names of the menu items may not be correct because I do not use the English locale on the watch.)