Official Sony Xperia Xz Premium G8141 Single Sim Stock Rom Ftf For Flashtool Verified [2021] -

Sony Xperia devices have unique DRM keys stored in the TA partition responsible for camera noise reduction, low-light photography, and proprietary display enhancements. Official stock ROMs respect these keys. Verified FTFs ensure the flash process does not accidentally wipe or overwrite the TA partition unless explicitly selected.

Removes custom ROMs, root access, or custom recoveries. Sony Xperia devices have unique DRM keys stored

You can confirm the FTF is because: