Virtually every media outlet took this remark as meant to differentiate Rmoney's position from President Obama's expression of support for same-sex marriage this week. ("Virtually" means every outlet I have seen or heard of, but leaves wiggle room in case some radio station in Sitka took a different view.)
But look at the words. What was Mitt doing? Clearly, he was assuring conservative Christians that he--along with all other mainstream Mormons--espouses monogamy. But you won't see any mention of that, except here.