I found it weird seeing her bow down to Arngeir an his mates, wonder if theres a deeper backstory to this? - would be really interesting.
No backstory at all, of course. These are just NPC "hotspots" that tell NPCs what to do when they occupy that spot, the same way your spouse decides whether to cook something, or use the alchemy lab, or sit in a chair. There are obviously hotspots that are not visible to the player but are visible to NPCs.