When Flip Flappers first introduces Cocona, she is trapped in a sterile classroom taking a test. The shifting of sand is heard rather than the ticking of a clock — an hourglass resembling a Rubin vase takes the place of a traditional clock face mounted on the wall above a white board.
Rubin’s vase — named after its creator, danish psychologist Edgar Rubin — shows two shapes only one of which can be recognized at any given time. You can see the hourglass, or you can see two faces with negative space between them. While your mind can recognize that there are two things to see available to you, your eye can only focus on one at a time.
This plays tricks with the way the human brain generally perceives objects — by establishing depth and separating figures or objects from the ground. Ambiguity, like the less distinct image of Rubin’s vase, allows our minds to take the lead in perceiving the object in front of us. Do you see an hourglass or two faces first?