Personal space is defined by the walls we create physically and emotionally. Those that cannot be seen are influenced by experience - both good and bad. Allowing rooms to expand and contract as needed. The physical barrier though sits in place, not moving from its foundation without an extraordinary amount of work. We allow others in as we wish, but to everyone else the window acts as the sole portal for visibility into who we are.
Items, carefully placed with the intent to be seen offer another window - not physical but seen with intent in to us.