The couch: g8 and c8
A couch horse (卧槽马) sits on the enemy's second rank beside the palace — g8 or c8 against a king on e9. From the trough it checks with a jump that nothing can block, because a horse has no line to close. The trap here is already sprung shut: Black's own advisors jam d9 and f9, and the crossed soldier on e7 seals the palace roof at e8. A horse mate is pure geometry — the king is not even attacked twice, he simply has nowhere left to stand. Find the jump into the trough.