The shell is transparent and affords a view onto a further cube inside. This inner cube accommodates the rooms for rotating exhibitions. Its limestone-clad wall surfaces receive grazing light from special perimeter luminaires.

The reflective properties of the facade were consciously and skilfully utilised by the architects and lighting designers. Whereas the vitreous, reflective cube strikingly sets itself apart from the commercial-looking surroundings by day, a differentiated image emerges with the onset of darkness.