what does this mean?

[Dan Lester]

My internal hard disk is Shadowfax, running Sequoia 15.3.1. I have a Passport daily backup. When I do SystemSettings>General>Startup Disk I see this
https://ibb.co/39LNJHtW
https://ibb.co/39LNJHtW

Why in the world is my Passport daily backup labelled MacOS 12.6.8???

I'm doing whole disk clones from one to the other. Is my backup somehow not getting an updated system? 12.6.8 is also what it is labelled in Disk Utility. Oh, by the way, that daily backup REALLY is getting updated with all my new files.

[Dan Lester]

OK, I'm gathering that this was just the OS under which the drive was formatted, rather than the OS that is actually resident on the drive. Seems kinda dumb.