They wouldn't have to show anything to imply it. Just a line like "I'll have/take her head"
If the Queen had spades, the implications of the skulls he's wearing are pretty blatant either way.>>93752326
They could probably get away with silhouetting it or seeing it in shadows, if they cut away at the last second and don't show the aftermath.
It's also being treated and advertised as a "movie event" so they might have a little more freedom.