A33Zab,
The link you posted is to a photo taken from the P1 seat, probably in its aft position.
AFAIK, we do not yet know where the captain sat or stood during his all-too-brief return to the cockpit. He may have managed to sit in the P3 seat, as I think you suggested.
Regret I don't have a plan of A330 seating, but the P3 seat is likely to be the one used by third crew members, including training and check pilots. It has to offer the best viewing position behind and between the two operating pilots, usually at the back of the centre console. It was my job to spend many hours in such a seat on the A320, so I'm only too familiar with the concept. You MUST be able to see everything to do that job properly, so there has to be such a seat.
Perhaps
PJ2 or
CONF_iture can comment.