A display unit comprising of at least one display sheet of a substantially rigid and foldable material divided into a plurality of panels by crease andor score lines that when erected forms a display unit with at least one concave presentation face. The upper portion expands a retaining member in the receiver cavity to capture the shank upper portion in the receiver. , and to be switched from the transparent state into the mirror state by means of dehydrogenation of the thin film in the range of about 20 C. An optional upward raising secondary bow is also described.