Looks like high winds may have been a contributing factor.
I'm guessing the wind "took hold" of the ship on the left, slowly pushing the stern to our left, swinging the bow into the ship on the right.
These big cruise ships have some kind of "side propulsion", don't they?
The bridge probably tried to compensate for the wind, but what they had might have been "not quite enough" to counter the pressure of the wind against the port side of the ship...