Newbie Q photos blurred and cropped in app

Hi
Newbie here! Can’t find the answer via search so apologies if it has been addressed before.

I have invested in MyCloud Home & transferred all my photos via Desktop App which took 20 hours. Mix of JPG and NEF raw files from Nikon mainly. Can view them OK in Desktop but the quality isn’t good via the mobile apps in iPhone and IPad - many of the images are blurry and cropped to a square. The drive has being ‘working away’ for about 2 days solid, chirping away in the corner. I think it is working it’s way through my folders changing the images?

What is the drive doing to my photos please and will I ever be able to use/see them via the mobile apps?

Thanks

The images are low quality thumbnails and not HD images.
Low quality thumbnails are extracted and then replaced by higher quality thumbnails in the background. Give it some time and you should start seeing clearly thumbnails.

Thank you I hope so, there is a lot of photos! I still cannot see them clearly after 3 days the device is still working !