Storage vs Memory in the context of Gas Cost

Question

I have two snippets -- one using memory, the other referencing storage:

function winnerName() public view
            returns (string memory winnerName_)
    {

        string memory winnerName_ = proposals[0].name;
    }

function winnerName() public view
            returns (string memory winnerName_)
    {

        string storage winnerName_ = proposals[0].name;
    }

The gas used for executing both snippets is the same (as per ganache). This seems surprising to me, given that memory creates a copy and thus is more expensive.

Is this an optimization under the hood? I've used truffle compile to compile the contract.