Wax is poured into the mold, leaving one side embossed and the other side flat. The flat side is then affixed to the paper. Therefore it would not be mirrored, the result of pouring sealing wax into a regular mold is essentially the same as the mold, but cast in wax; if OP's widget were a wax mold, the resulting cast wax would look exactly like the mold, but not hollow.
I'm leaning more towards button cover.
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