The QR Code generated for adding the TOTP Key to an app, in the "Verification Code via App" method enabling page, lacks a "quiet zone" (i.e. a padding around the matrix) that is required to enable QR Code readers to properly detect the QR Code matrix. On lighter styles, like the default one for XenForo, this poses no problem as the background around the QR Code is almost white. But if the style has darker background colors (or, in the worst case, black), the lack of a quiet zone around the QR Code makes it very difficult for the QR Code readers—or impossible— to detect the QR Code displayed on the screen. While this can, of course, be fixed at the style level, having the quiet zone around the QR Code by default would always ensure that the code can be easily read despite of the background color of the style, and thus, requiring no special tweaks at the style level.