Preview Images

I just purchased a 1tb passport wirelesss.  No problem with updating firmware or importing picture/video files directly from SD.  Transfer time was reasonable.  

However, after completion of transfer, the unit went into “building preview images” mode and it is taking forever.  Is there a way to shutoff the “building preview images” function?  If not, if I just turnoff the passport drive, what will happen?  files damage, missing or nothing?  Thanks for the help.

Welcome to the Community.

It will not affect your hard drive. However, the process is likely to resume the next time the device is operational.