I wouldn't be surprised if the bills themselves are marked with specimen or some...

burnt-resistor · 2025-07-01T17:38:53 1751391533

I agree. The "money" probably has the shape and appearance of money, but isn't legal tender out of concern risk management and theft.

The cube is almost certainly hollow, to cut weight and cost.

It's the idea of what a cube of $1m would look like. It should at least fulfill that requirement faithfully.

nativeit · 2025-07-01T17:45:32 1751391932

Someone else had mentioned these were retired dollar bills (aka, otherwise headed to the incinerator) but I don't know the provenance of this information.