A method includes, at a computer system with a display, a housing, and an attachment mechanism, detecting attachment of an accessory to the computer system, where the accessory, while attached, has a predetermined orientation relative to the attachment mechanism, and in response to detecting the attachment of the accessory to the computer system in accordance with a determination that the accessory is a first accessory with first physical dimensions, displaying, on the display, a first visual indication that the accessory has been attached to the computer system, wherein the first visual indication indicates at least one property of the first physical dimensions, and in accordance with a determination that the accessory is a second accessory with second physical dimensions that are different from the first physical dimensions, displaying, on the display a second visual indication that the accessory has been attached to the computer system, wherein the second visual indication indicates at least one property of the second physical dimensions and the second visual indication is different from the first visual indication.