A panel assembly includes a panel (10), a mounting apparatus (50), a light-reflecting member (30) and a rotary member (70). The panel includes a light-pervious area (131) and an opaque area. The mounting apparatus is mounted in an inside of the panel. The light-reflecting member is pivotably coupled to the mounting apparatus. The light-reflecting member has an engaging member (371) and a light-pervious portion (35) for emitting light. The rotary member is rotatably attached to the mounting apparatus and accessible from an outside of the panel, and the rotary member being meshed with the engaging member of the light-reflecting member for driving the light-reflecting member to rotate between a first position where the light-pervious portion is aligned with the light-pervious area and a second position where the light-pervious portion faces toward the opaque area of the panel.