Well it is weird in French too. The meaning is that the original document counts as “one copy” and its copy as a “second copy”, both of which should be signed by both parties.

To my understanding, this is a way to allow both parties to have an “original contract” in hands. Otherwise, one party would have the original document and the other party would not. With “signing 2 (original) documents”, both parties have the original document.

I don’t find this weird, it’s a contract made in two copies, signed by the two parties at the same time so that both get the same legal paper at the same time.

There is no reason why one party gets a “better” version of the contract, and this is what we get all the time when we sign a contract in France.

Indeed, the first blank is the city where you are signing and the second one is the day when both parties signed.