Since the roleplay subforum isn't up, I'm making this in here. The point of this thread is to fill the room (of changing size/volume) with whatever and wherever your imagination takes you, and any poor visitors to your 'habitat' will see the room (and you whoever else in it) as such until someone else changes it, kinda like that holo room in 'Spy kids' 3nodding
The one thing that doesn't change is the door(knob/frame), so people can leave.

~~~

Seirya stands in the middle of what appears to be an empty, white-washed room. The door she had entered by was only marked by the doorknob inset into the wall - otherwise, the room was featureless.
She sits down onto a gilded chair, upholstered in red velvet, that appears behind her just before she completely surrenders her balance, and surveys the plain room.

"What can I do with nothing?" she muses aloud, although a smile spreads across her face.

"Anything and everything."

The wall facing her is pushed back 100 meters, as is the door within it, forming a long hall. A wooden dining table appears in the middle of the room, with Seirya at the head and the door at the fartherest end. A tablecloth flies in from nowhere over her head to settle on the table, and cutlery as well as various china appear on their own to weigh it down.
A venitian chandelier grows out of the ceiling to greatly illuminate the room, showing that the other walls have morphed their white colour into a pattern of roses, and a plush velvet carpet now covers the floor.
Exact copies of her own chair march in through the door to line up along the table like so many soldiers, ceasing their movement abruptly once all the places are filled. The room is eerily silent now that there is no motion, but as soon as Seirya realises this, the air fills with the soft melody of a string quartet.

The table is still empty of food, but why set out a course when any person who enters can have their individual favourites?

Seirya props her head indulgently on the table, awaiting what people might come in.

"Come into my parlour..."