That's back when Apple made everything 3-Dish and liquid and transparent. It did indeed change a whole 5-year chunk of UI designs. Maybe it was even the first skeumorphism...it looks like water
What innovations were new to OS X? In several cases it copied features from other systems and then did a worse job of implementing them than the original. GUI search was copied from BeOS and less powerful and more cumbersome. Workspaces were copied from unix UIs, and feel roughly bolted-on because the system is application centric not window centric. The strength in OSX was in bread and butter stuff like consistent UI and drivers that work.
The only thing that was mildly new was the traffic light and horizontal stripes. We'll have to see if people still respect that in a few decades. I suspect we will instead look back at it as influential in the way in the way that flares or the Ford Anglia 105E were influential, perhaps asking "what was wrong with the world that so many people thought this kitsch to be a good idea".