The spindles are spaced close together for a refined look and back comfort in both straight [ upper left picture] and fan back [ rest of pictures].
The backs of my chairs used as occasional chairs have a different angle, that I refer to as a slouch angle, than my dining chairs. The angle of the seat to the floor is also different, this makes for a much more comfortable chair than you may be used to, with your experience of a Windsor dining chair.
The backs of my chairs are quite high which allows for a small pillow to be hung from the comb, for the ultimate in napping comfort.!!!
This is not my idea or even a new idea these chairs were often referred to as shawl backs in England, where the shawl would be folded as a pillow at the top and the rest would hang down to keep off drafts.
Each chair is made with hand tools, shaped by adze, drawknife ,shave and sweat, so each spindle has a multitude of little facets that make it very tactile and distinctive. All tenons are wedged for security, with contrasting woods for aesthetics.