Corresponds to whether the player has already seen the image for the following rooms:

Bit	Room ID	Room Name
0	3	In the Field
1	14	The Monastery
2	28	The King's Chamber
3	39	The Oil Room
4	40	The Acid Room
5	61	The Sea Cavern
6	18	Within the Long Barrow
7	43	The Hall of the Black Knight

Bit	Room ID	Room Name
0	41	The Treasury
1	19	At the Edge of the Sea
2	N/A	N/A
3	N/A	N/A
4	N/A	N/A
5	N/A	N/A
6	N/A	N/A
7	N/A	N/A

HandlerDisplayRoomImage tests and sets the bit for the current room. The bit number is the room's place in Table_RoomsWithImages.