It is your lead. Your third pile shows one visible card, the 4♥. Beneath it waits that pile’s hidden bottom card.
If you lead the 4♥ now, list what happens, in order, before your opponent responds.
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Answer
First, the 4♥ leaves the pile and becomes your lead card. Second, the pile reveals what sits underneath: the true bottom card. Third, because it is a bottom card, it is never tested for Tarok-or-King and never shown to the table: it slides straight into your hand, known only to you. Fourth, the pile is now empty, gone from the table. Only after all four steps does your opponent even see the 4♥ and choose an answer: every reveal in Strawman resolves in full before the trick moves on.