You can continue afterwards in the replies, as long as they are not taxing:
- Some big trees in between houses and around towns, and sometimes close to the shores.
- Small wavy water streams that reach into the cities or settlements, probably with some sparse small fishes
- Bards, jesters and live taverns (RadiantAI)
- Women washing clothes in rivers (RadiantAI)
- Wooden bridges
- Lit lanterns in house at night
- Big jars and vases in front of homes for plants
- Sounds of insects and crickets
- Birds standing on the floor or trees that may fly away as you approach
- Occasional mosquito clouds and single butterflies
- Occasional tamed wolf next to a house or tent in the Nordic settlements
- Occasional small plants growing in the rocky streets of a full blown city, or vines from big rocky walls
Just be sure not to ask for complex mechanisms like tons of people, animals, pets, bunnies and bugs, because that would tax the AI too much and will be left aside. Better go for those small details and design concepts that you hadn't thought before and have an easier chance of being there included.
Again, the keywords are occasional and sparse in case of living creatures.
Edit: i'll keep adding more from replies and my own ideas overtime.