Girls’ Generation member Taeyeon looked alarmingly too thin as she posed to take a photo next to member Hyoyeon.

The photo had been taken back stage at the SM Town Concert, where both artists were wearing black crop tops with denim pants. Taeyeon looked comparatively skinnier than Hyoyeon, who recently admitted she lost 9kg. The frame Taeyeon's rib cage showed through her fair white skin, leading to many fans now worried about Taeyeon's weight loss. Even though Hyoyeon is also slim, standing next to Taeyeon, it was not comparable.