OptionalActiveIdentities the platform reports as speaking, most recent first (a meeting room's active-speaker list).
OptionalMovesThe user's moves, oldest first. Only each surface's latest move counts, so a host may keep just those, in order.
Everyone in the session. The local user has Role: 'self'.
OptionalPinnedA participant the user pinned to the stage.
OptionalShowWhether the user's own tile is among the other participants. Defaults to true.
OptionalSurfacesSurfaces that can be placed, in the order they appeared.
What the stage is laid out from.