More room. The same place.

Trace light through the moving panel. Pause or drag to inspect the fold.

A ray through the unfolding screen Top-down optical analogy. A light ray enters an illustrative glass layer, bends inside it, then leaves. Faint rays spread around the outgoing ray to illustrate diffusion. The spread increases during the fold and vanishes at the endpoints. TOP-DOWN OPTICAL ANALOGY Image plane Hinge Moving panel Toward your eye Glass thickness and diffusion exaggerated for clarity.
Traced rayDiffusion / blurSurface normal
ClosedEdge-onOpen

Closed · sharp

The ray passes straight through. There is no added diffusion.

A way to picture the illusion, not the phone's optics. We trace refraction through an imagined glass layer (index 1.45), then add illustrative diffusion. Refraction alone doesn't create this blur. Real screens are opaque; our reconstruction controls image sampling, blur, and brightness in software.