The iPhone Duo's foldable display features an invisible crease, but the area above the hinge is soft and depresses when pressed. According to Weibo user Kang, this softness can lead to visible wrinkles that snap back when the finger moves. Multiple units exhibit the same behavior, suggesting a design characteristic rather than a defect.
Ice Universe speculates this may relate to Apple's rumored variable-thickness ultra-thin glass (UTG), which has a thinner central folding region and thicker surrounding areas. Corning's variable-thickness glass (Vt G) allows for effortless bendability at the hinge while maintaining durability elsewhere. Apple has not confirmed if it is using Vt G.
The inner display's screen protector is replaceable, potentially making this an easy fix. However, long-term durability remains a concern as the soft area may develop issues over time.
Source: GSMArena · Summarized by HeadlinesBriefing