How is it possible that an address is a contract on one chain and a regular account on another chain?

I happen to come across an address which appears to be an NFT contract on the Polygon chain but a regular EOA on the Ethereum chain.

Ethereum: https://etherscan.io/address/0x2953399124f0cbb46d2cbacd8a89cf0599974963
Polygon: https://polygonscan.com/address/0x2953399124f0cbb46d2cbacd8a89cf0599974963

In other to make transactions with that address as an EOA, the person would need the private key to it. Yet, if that address can also be a contract, this somehow means that the person has the private key to the contract address?

How is this even possible?