The shadow that fell on the wall in Fiskars, Finland reminded me of balance. There is shadow, there is light. And together they are different halves of the same whole. And even though you seem to be facing a wall, there is light above. Much like in life.
(And this, by the way, was the ancient Egyptian view of life: it was necessary to have both sides represented to create ma'at or the proper way of things: light and shadow, dry and moist, balance and chaos, day and night, male and female. Both sides were considered equal in importance.)