The mobile presets can be used on your mobile phone in the FREE Lightroom app (without an Adobe Lightroom subscription). Therefore, the files are different and are specifically made for Android and iPhone photos, and other JPEG photos. The desktop presets are .xmp or .lrtemplate files for the desktop apps Lightroom and Lightroom Classic (on both Windows and Mac, with subscription). These presets are optimized for RAW photo files, but will also work with JPEG photos.