... that the bottle design has changed slightly?
The shoulders are no longer horizontal but rounded. According to the SAs, the newer bottle design came about because it was felt the older design wasn't as comfortable to hold.
But the new bottle design hasn't been restricted to Opus VI - all future Opus batches will now be housed in the new bottle.
Furthermore, although I haven't checked the other Opuses, the colour of the juice in the new bottle design for Opus I is darker. Now it's a dark orange colour. Difference in batches or a reformulation, I have no idea.
It's a nice subtle change in the bottle.