That description is everything that is wrong with the anti-gay position.
An heirloom painting hanging in the family home is the PROPERTY of that family.
But marriage does NOT belong to one family! It is not your personal possession, to be hoarded from everyone else! You have to SHARE!! Do whatever you want with your VERSION of the painting that you've brought to your home, but don't pretend that what someone else does with THEIR version will have any affect on yours.
A more accurate analogy, using marriage as a precious painting, would be one that describes it as hanging in a PUBLIC gallery, NOT a private home, while fundamentalist extremists and bigots cordon off the gallery, and only allow "approved" people to come in for a look.
Well, their time as guardians of the gallery is ending. They couldn't do it right, with a 50% divorce rate and rampant discrimination. Time for people who know how to be fair, compassionate and inclusive to be put in charge.