Hang an empty frame on a wall and watch what happens. Visitors lean in. They search for the work, find none, and are briefly, wonderfully unsettled. Then — and this is the part we enjoy — they begin to supply it themselves.
The empty frame is not a failure of decoration. It is a question, posed politely, and left open. Most art answers on your behalf. The empty frame has the courtesy to let you answer, or to decline.
The absence is load-bearing. Fill it and you have merely a frame around a thing; leave it and you have the thing itself.
We are often asked what belongs inside our frames. Nothing, we say, and mean it as a specification rather than an apology. A small, framed portion of the room, promoted to significance by a border and a decision.
There is, admittedly, a commercial awkwardness to selling frames around nothing. We have made our peace with it. So, in time, do our customers, who report that the empty frame is the only thing on the wall that never goes out of fashion — because it was never, strictly, in it.