Breaking the 4th Wall
Reading through Ariane DeVere’s transcript of TFP:
MYCROFT: She knew things she should never have known …
(Nearby, an overweight boy stands on one of a row of stepping stones across a stream. Wearing yellow boots, jeans and an olive-coloured jumper, he tosses a pebble into the water, perhaps attempting and failing to skim it. He looks across towards adult Mycroft, who turns away from him. Beyond him, little Eurus has her back to him and is watching as seven year old Sherlock, wearing red trousers, wellington boots and a dark yellow patterned jumper and with a pirate hat on his head, slashes at the water with his plastic sword. Adult Mycroft bends down and picks up a large pebble from the water’s edge.)
MYCROFT (in 211B): … as if she was somehow aware of truths beyond the normal scope.
(He opens his hand in front of him. His fingers are wet and a large pebble lies in his palm. In his mind, young Eurus turns around on the beach and looks directly at him. Mycroft looks startled.)
EURUS: You look funny grown up.
(In 221B, Mycroft straightens up in his chair a little, staring towards the fireplace.)
So, um. Eurus (who is either a story come to life or a living person turned into a story) interrupts the story being told within the story to address the storyteller.
That’s awfully metafictional.