It's hard to see what is going on here, it's just a picture of the back of a woman's head, there is no action, not even a possible story to tell.
What there is though, are some detail of her hair do. And I think you wanted to tell or show more than just that.
For a photograph like what I think you had in mind to be successful, you need to show some action and expression in the people you are photographing.
Some suggestions would be showing them doing each others hair, getting dressed, something that involves action and that the person(any one for that matter) viewing the photograph can relate to. The photograph you have here doesn't do much in these regards.
Am I being helpful?
Good Luck on your next wedding!
Brian