Recovered files are correct size but empty

I have just accidentally shift-deleted a folder full of photos. I had many hopes that instant attempt to recover them would be successful, but... Nothing works. Recuva shows "excellent" condition and lists all the files, but hex editor shows zeroes and opening recovered file with notepad shows blank pages.

It is not my system disk, nothing was written over the info, SSD drive, NTFS partition. What could be wrong?

Nothing. A deleted file on an SSD is subject to TRIM, which means that any attempt to read the deleted file's pages will return zeroes. It's just how SSD's work under NTFS. Unfortunately there is no way I know to recover those deleted files.