According to this documentation, ownPaymentPubKeyHash is:
Get the hash of a public key belonging to the wallet that runs this contract. * Any funds paid to this public key hash will be treated as the wallet's own funds * The wallet is able to sign transactions with the private key of this public key, for example, if the public key is added to the requiredSignatures field of Tx. * There is a 1-n relationship between wallets and public keys (although in the mockchain n=1)
It sounds very much like a wallet address. But is it?