For you the sender (Bob): the addresses you see in the outputs field are the recipient address (Mary's) and your change address.
For the recipient (Mary): to know the address(es) of the sender, she needs to copy the transaction ID and look it up on any blockexplorer. The sender's address(es) is listed in the inputs field.
Note: there is no way for Mary to be 100% sure that the sender is Bob unless he is the only one she gave her address to or if he signs a message with the sending address.