1. A method comprising: displaying content on a transparent or semi-transparent display of a head-mountable device (HMD), wherein the displayed content is perceived by a wearer of the HMD as being superimposed over a real-world field-of-view seen through the transparent or semi-transparent display; making, by the HMD, a determination that a trigger event occurred; responsive to making the determination that the trigger event occurred, both: (i) generating, by the HMD, a first image of the displayed content, and (ii) causing, by the HMD, a camera to capture a second image of the real-world field-of-view associated with the HMD; and generating, by the HMD, a composite image that combines the generated first image, the captured second image, and a glass-texture effect image by overlaying the generated first image on the glass-texture effect image and overlaying the glass-texture effect image on the captured second image, wherein the glass-texture effect image is neither displayed on the display of the HMD nor part of the real-world field-of-view associated with the HMD.