IMO the monster is in a good place, the only issue it has is once it's near the player, it won't leave the proximity, which makes hiding kind of useless as he will most likely come back to the same room.
All that has to be done is after a while of being in the proximity, it'll go out of the range for a little while to give the player a chance to leave and go on their way.
I also think it should be a little bit more clearer that the flashlight can slow the monster down as the drawing on the wall can be missed easily.
Player is also faster than the monster without putting any paintings on the puzzle, so it's just about players getting used to the environment and learning how the enemy works.