The hinge is defined to the studio as a design tool for design strategies; how seed and field relate to each other physically (they are not supposed to intersect with each other) & how different parts of the design interrelate with each other. It is about relating elements through the hinge, redefining their relation and creating spaces. However, not every point is emphasized as a hinge. While defining the hinge, we also need to have a strategy.
We can see the similar relationships but while one is entitled as hinge, the other one is not. So, what is the difference? Why do you think this is a hinge? In order to differentiate the hinge from the other relationships, we need to consider about textual, dimensional, and formal details.
*Hinge is not exact construct but it is about how two things come together and make something.
Scale change of the elements maybe makes the hinge. Also, texture, thickness can be applied as a hinge. The elements which are not touch each other and the gap between them creates the hinge.