You are looking down the cellar stairs.
Light is coming from an exposed bulb on the cellar ceiling and from a small window in the back. Some noise is coming a running computer down there. That is the server this tour is was running on. The shelves and floor seem to be filled with computer monitors, cabling, cardboard boxes, a sowing machine, sleeping bag and assorted tools. Dangling from the wires you see a network switch, next some telephone sockets. Despite the looks, it all seems to function properly.
A small 3 step stairs lead up from the cellar to the corridor.