It would appear as though HM has been tinkering a bit with her jewellery.
As noted by Ella Kay on her "From Her Majesty's Jewel Vault" site, it would appear as though The Queen has had the fringes on her 5 Stand Pearl Fringe Watch shortened.
The fringes - 4 each on either side of the diamond encrusted face surround of her Patek Philippe watch - originally consisted of the 2 outer fringes on each side having 3 pearls and the inner 2 fringes having 4 pearls. The pearls are graduated (smaller toward the face) and have small silver spacer beads between them.
It looks as if HM has shorted each fringe to only one pearl each.