Glass is widely recognized as a built-in iPhone notification and text alert tone from Apple's mobile ecosystem. Online, creators use it as a quick shorthand for a message arriving, a sudden distraction, or someone getting exposed by their phone. Its popularity comes from how instantly recognizable and brief it is, similar to a ding sound effect or a Discord notification in editing language. That familiarity keeps it useful in short-form videos, comedy clips, and everyday social media edits.