It related to putting an image on a piece of metal money.

它与将图像放在金属货币上有关。

The capsule is smaller than a coin, a piece of metal money.

该胶囊比一枚硬币（即一块金属货币）还小。

America's central bank, the Federal Reserve System, announced in June that the supply system for metal money had been affected.

作为美国央行的美联储于六月宣布金属货币的供应体系已经受到影响。

Literally, we talk about the flip side of a coin – a small piece of metal money.

从字面上看，我们谈论的是硬币的反面——一小块金属钱。