The appearance of long necks
To provide some context for the women of the Kayan Lahwi tribe, they adhere to a long line of tradition. At first, all females must wear a single ring. They may add another ring at a later date. This is to prevent the weight from crushing the collarbones simultaneously.
This ring must be worn at night as well. There is an illusion of a long neck because of the rings. It is really compressing the collarbone. It’s a domino effect from here on out. Compression of the rib cage results in the deformation of the clavicle.