That's assuming they are official scarves
You are not allowed to sell scarves with a trademarked picture on it.
A release of any kind is only required if the photo makes it appear that the subject of the photo advocates a particular point of view (supporting a product, idea, ideology, relgious or political position). Simply put, you can't publish an image in a way that makes a person appear that they support something without their permission. If the photo would imply that association, then the entity that publishes the photo—which usually isn't the photographer—is responsible for getting permission from that person.