When I right-click on an icon on the desktop (Plasma 5.4) two menus appears: the one regarding the desktop settings (that is the one you get when you right-click anywhere on the desktop) and "behind" this one, the menu related to the icon itself.

Quite similar to what this guys goes through: https://www.youtube.com/watch?v=D4UJs-AzmO4

Very disturbing.