Embodiments of the disclosure relate to a cover for an electronic device. The cover can be deployed on a transparent surface of the electronic device and can reversibly occlude the view through the transparent surface. In certain embodiments, the cover can include a closed bounding surface region that is transparent and has a specific volume. The bounding surface can define an interior open space that can be partitioned into multiple cavities, where nearest-neighboring cavities can share a surface that defines each of such cavities. In one embodiment, in order to occlude the view through the transparent surface, an opaque liquid can be injected into the cavities, where the liquid can solidify and, thus, can form an opaque solid layer. To reverse such an occlusion and, effectively, uncover the transparent surface, the solid layer can be melted by applying a suitable voltage to at least one of the multiple cavities.