Ah - ok. Alright - I'm going to venture out on another uninformed limb here - can you place the different paintings in the scene as sprites and toggle vis on the sprites?
Looking at a couple of the example games, there are some fairly large images handled as sprites. Probably not super-efficient, but then if you're doing dialog / adventure action and don't need to run simulations or a lot of heavy updating, it might still work for what you're trying to do...maybe?
regards,
Rowan