Idiom help

[Anewguest]

Imagine the following: a room is full of toys then someone takes all the toys away and the room is empty (except the furniture, carpet etc.). Is there an idiom/saying to describe this emptiness?
"Empty as a banker's heart" doesn't fit. At least not in my case.

[Chicchick]

The cup is half empty?

When people see a cup half full they are supposed to be an optimist.

When they see it as half empty they are supposed to be a pessimist.