Stones skillfully fitted together structurally, with nothing else keeping them in place, can create a kind of visual conversation.
It is a conversation between positive and negative space.
And it is always interesting.
Walls having spaces in them that are too wide lose this give- and-take connection. The relationships, the comparisons are lost. There is little conversation.
Likewise if the stones in the wall are spaced too close together, too tight, if the joints are too 'the same', the thing can become just as uninteresting. The conversation doesn't have opportunity to get started. There is no dialogue. The positives outweigh the negatives. The whole thing becomes a monologue, a lecture, a boring dissertation.
The space between the wall stones (and the space between us all) is so very important, and worth talking about again sometime.