The inside and the outside
Adolf Loos said one the great heights of design was a saville row suit. On the outside a projection of uniform elegance which made the wearer look their best; whist on the inside was a complex myriad of nips, pulls, tucks seams to create what is essentially an illusion.
Our sentry tool sheds always have a deep contrast between the interior and exterior. Not only for delight but as a design principle that internal and external are very different places indeed.