I arrived at Winterbourne Bassett early tea-time today ( 29th July), as the formation has already been cut out, I didn't stay long. I did notice that the crop cutting stopped about a foot before the edge. Obviously there is plenty of signs of crop disturbance, however on the 'untouched' outer ring, the crop is bent at the first node and flowing anti-clockwise. The centre is clear, possibly a splayed out centre piece? As i walked around, and carefully lifted up the cuttings, in some areas, the still planted whole stems are laid clockwise. Maybe because of the cutting, or maybe because of 'features'.
 
JIC