>>96334974
In terms of worldbuilding, the approach to the setting has become a lot more grounded. It's still a very high fantasy world, flowing into the mythological, but we started to see it more and more through the eyes of everyday "normal" people. For example, see the difference in maps put out in the modern day vs examples of """maps""" on launch you can see higher up in the thread. This has its pros and cons (sometimes modern day aos is a bit too mudcore imo).
In terms of minis, you can really see the transition from rank n flank to round skirmish. Lots of the early minis released had a way more rigid look. See early liberators and infamously slayers. There's a reason they primaris'd the stormcast like 6 years after release.
Also the way the game is structured in general, early aos used to center around grand alliances a lot more. Lots of soup 'armies' (you weren't really supposed to play them alone, but the webstore listed several armies like swifthawk agents or whatever with like 3 units). Pestilens, bonesplitterz, beastclaw raiders getting their own battletomes, stuff like that. They consolidated it to the much more standard battletomes we have now.