Two different announcements from the same iPhone with the same iTunes connection Last time I connected my iPhone to iTunes and I received two different announcements while restoring the iPhone:

first:




  Last archive: Today 21:53


second:




  Last archive:
  Your iPhone has never been backed up to this computer.


Why it happens like that? The second one is not true...
After restoring your device iTunes will not link it to the previous backup. Your backup whatsoever nonetheless exists. You can find a list of your backups in iTunes Preferences > Devices / If you're using iTunes for Windows, choose Edit > Devices. 

By what I understood your first screenshot is before restoring and your second screenshot is after restoring, therefore it makes sense.

Nothing to worry about. Doing a new backup will not delete your old one.