Understanding 'Transfer of Property' through a Street Food Analogy

Imagine you order a piping hot pani puri from a street vendor. You pay cash upfront, but the vendor hasn't given you the puri yet. Now, if the vendor transfers the ownership of the store to his friend, who hasn't even given you the puri, who has the ownership rights to the puri - the original vendor or his friend? In the eyes of law, the ownership of the puri hasn't transferred yet. It's like a 'promise to sell' in contract law. But with the transfer of property, it's more like the transfer is done with the delivery of the puri. If the vendor transfers the ownership before delivering the puri, it's called an 'executor promise'. The friend now has the rights to the puri, but the contract is still pending. Make sense?