Sigfried666 said: The problem is that, with so many witnesses, he can't turn over the chessboard.
That doesn't, however, disqualify the possibility. For example, someone could detonate a small bomb outside the window, distracting everyong from the game.
That's not checkmate though, this game will likely end in a draw by threefold repetition . Ignoring her knight & assuming it's his turn, the game will play out thus: Gold queen: E7 to B7; white rook B2 to B7 takes gold queen; gold rook C8 to B8; white rook B7 to B8 takes gold rook, check; gold rook D8 to B8 takes white rook; white rook B1 to B8 takes gold rook, check; gold king A8 to B8 takes white rook; white queen A6 to B5 check; gold king B8 to C8; white Queen B5 to C6; Gold king C8 to B8 and repeat the last two moves for a draw.