Heidegger, ready-to-hand an object that is being used tends to recede in the user’s perception. So long as it is functioning well, a mouse tends to disappear in a user’s thoughts; the user’s experience is that the hand is directly manipulating the cursor upon the screen. The mouse is not thought of, or if it is, it is a multistability, rhetorically speaking. The user might refer to a variety of actions that they do with the mouse, grabbing, throwing, dropping, drawing, scrolling, that all have an analog in different material references.
When something breaks, it becomes conspicuous in a startling way. No need to flash a translucent picture of a mouse on the screen when the batteries run low. The mouse that has run out of batteries intermittently calls attention to itself by ceasing to function. Things may also become noticeable as broken if a part or piece is missing. If you are trying to turn on the light in the room, and no one has installed bulbs in the fixtures, or trying to light a stove, but the flint that creates the spark has not been installed. An object might also emerge in attention if it is blocking someone from achieving a goal. For instance, if, while a worker is on vacation, their office has been filled with extra chairs. Perhaps the person returns early, and, while the experience is not precisely broken, the chairs become quite noticeable as blocking access to the office. The chairs become active in a way that was not intended in their original design.