Android application package named Emotn UI, version 1.0.8.9, about 14.7 MB in size. The name indicates a launcher or user-interface app, typically installed on Android TV boxes and smart projectors to replace the stock home screen. It is not a schematic or firmware image and does not touch the bootloader. An APK is installed by sideloading through a file manager, a USB stick or ADB. Check that the device runs a compatible Android version and keep the original launcher available in case the new interface misbehaves.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @tv_software. Enginerys does not host this file.