I think that that they would also shoot out of sequence if an episode contained multiple time periods and required actors to play more than one character.
I saw the 2012 several times but I have no recollection of those paintings. Vicki was played by Bella Heathcote and Carolyn was played by Chloe Grace Moretz. Both actresses work frequently. Chloe has been in more high profile projects such as If I Stay and the remake of Carrie.