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

Bit	Room ID	Room Name
0	2	A Wooded Vale
1	7	The Evaporation Pits
2	16	The Shrine Of The Nemed
3	23	The Burial Pit
4	73	The Main Courtyard
5	56	The Deserted Broch
6	67	The Crystal Cavern
7	64	The Circle of Stones

Bit	Room ID	Room Name
0	79	The Fomorians' Cavern
1	42	The Lake
2	82	The Danaan Settlement
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

Used by the routine at Handler_DisplayRoomImage but uses the bit index from Table_RoomsWithImages.