Problem accessing old G4 hard drive

I successfully used an EZQuest Hard Drive case to access the hard drive I'd removed from my old G4 tower.

But now when I open iPhoto it just goes to the iMac's iPhoto, not the G4 hard drive -- would that have anything to do with the fact that the G4 hard drive is also titled 'Macintosh HD'? If so, how to get around that?

And when I try to open iTunes on the G4 hard drive I get the message: The file "iTunes Library" can not be read because it was created by a newer version of iTunes" (I would think it would say 'older' version of iTunes). I'm confused about what''s going on.