The chin is the space below the smartphone display. It acts as a frame but creates the appearance of asymmetry because the side indents are much narrower. In older versions of smartphones, the chin was where the touch controls were located, but today this area is empty, acting only as part of the design.
The so-called chin is present even on frameless smartphones. Manufacturers leave it as a traditional element, not wanting to disturb the design of the front surface of the smartphone formed over the years.
