I think it's about the marriage as well. The wife is supposed to give a ring to the husband, and vice versa. She can't very well give him a ring that he already was using for years before meeting her, then it's not from her.

It is a confirmation that this is less than a normal marriage. It's consistent with the reports that Obama is gay. Also consistent with that is that he was wearing a ring in the wedding-ring position for years, which could deflect questions about "where's his girlfriend" when he was never seen close to a female. Everyone would think he was already married.