You are standing, or attempting to stand, in a room for which you are now clearly too large...
You appear to have just missed a dinner party; at any rate, the table is still spread with food. A dish of mushrooms has been knocked onto the floor and one of your feet is planted in it. Although the air is summery, the room's little fireplace contains a small but enthusiastic fire. To your right you see a round door through which you may be able to exit. There are two windows in the same (amazingly thick) wall; stooping, you see that they face downhill towards a distant stream. Behind you a passageway leads into the hill.
(Sorry, all passages from this point are yet to be dug. Better go back through the mirror.)