As Lukas climbs up to the door, he can stand on the machine and look inside. There is a room, about 15 feet square, clearly inhabiting cross-dimensional space. There are about a dozen round metal balls, like the kind that was rolled into the machine. There are four metal rods which the men inside before were using as crowbars to roll the ball. There is a slight upslope, perhaps of 1 degree, between the back of the room (where the balls are) and the lip of the doorway itself. There's no door jamb, or frame - the floor is unnaturally smooth right to the lip of the door.
There is a door inside; it does not seem fixed by hinges of any sort, but it is attached to the doorway. This door is set on the left side, from the perspective of being outside the door. Lukas cannot put a finger under it to see if it swings - there appears to be no space between the bottom of the door and the smooth floor.
The room is umber-colored inside; the walls seem less the solid in appearance ... and although Lukas can put his hand flat on the floor and feel its concreteness; his eyes tell him the floor is - for lack of a better word - oozing. There is a slight shift in the coloration that causes this effect. When Lukas' eyes are level with the floor, he can see the plane of the floor clearly; but when he lifts his eyes and looks down, that clarity evaporates. The perspective is thus disconcerting - and causes a slight illness in the belly.
Knowledge further than that will require climbing into the room.