A tangent exists when two elements barely touch, but do not overlap. A viewer may find it difficult to tell which element is in front of the other, leading to spatial confusion (figure/ground ambiguity). A tangent may create compositional imbalance by attracting unwanted attention, but with consideration, an artist may exploit the visual tension and confusion for specific social concerns or illusion.

Sometimes a tangent can be used deliberately:

Michelangelo. Creation of Adam. 1510.