Is there some sort of error you face?
Are you importing the images from Camera Roll?
The images should be able to import just fine, just a matter of putting the images into a folder that Lightroom Mobile is able to view. The Camera folder is one folder we look at.
Once saved, I'm assuming it goes to a folder that we can import from perhaps?
Just a Note: Importing NEF files is only an option on the iOS version of Lightroom Mobile at this time. Some Android devices allow for DNG capture and Lightroom mobile supports those DNGs
Are these images taken with your phone? If not, what file format are they? Can you perhaps post a shared link to one of the photos so we can try to reproduce this error?
Let us know!