If Ib and Garry try to enter the room without the Candle Painting, they will be unable to see, so cannot progress. Garry also cannot use his lighter, because it has run out of fuel.
Paintings are located on the northern wall. Malice's True Form is on the northwest side, and after Ib and Garry examine it, it will leave its frame when they walk away. The middle north wall has a switch to activate the Truant Seconds Hand, required to complete the puzzle. The northeast corner will have Prelude to Wine.
If Ib comes to the Dungeon without Garry and takes his lighter, she will be unable to use it in this room, even if she doesn't burn Mary's painting. This could mean that another force is keeping the lighter from being lit, not just it running out of oil.