First photo, taken 19th July 2013. You're looking at the arc of brown circular blobs in the grass, each about 3' across
Surveying the parch marks, July 23rd 2013. The one immediately to the left of Tim is that for Stone 17.
The Stonehole for Stone 17 wasn't detected in the geophys survey a couple of years ago and has led some archaeologists to consider the possibility that Stonehenge was never completed. The evidence of this particular parch mark is now causing a rethink.
Z-holes at the feet of Tim, Cosmin (in the HiVis), immediately in front of the camera at the bottom of the frame and extending in an arc beyond Tim outside the sarsen circle. The chap kneeling down is EH's Mark Bowden who is draughting a scale drawing of the positions.
The Z-hole parch marks are interesting too - several of the positions having not been recorded before, but now standing out quite clearly.
Genuine new information - there'll be an article about this in the next issue of British Archaeology.