As Junne remarked in his comment below, this young woman belongs to the tribe of the Long Neck People. We were told that she is a member of an almost mythical Burmese-Thai tribal group the Pa Dong Karen. Women of the tribe have worn ornamental brass rings for centuries. Although the exact reasons have been lost in the myths of time, the end result is world famous. Like many tribes in Africa, they endeavor to stretch their necks, slowly, a ring at a time.