what is the lore purpose of the sex scenes in the trailer?
Lore wise? Probably nothing.
It's more of an insight into the nature of how people feel about the circumstances being depicted.
The brutal act of ritually burning someone alive isn't a mere execution. It is something that people quite literally revel in.
All of the trailer is showing the light in which this act is seen. From the pyre in the shape of a person, to the festivities that are taking place with alcohol, music and food. This isn't an act of corporal punishment, but something that is seen as celebratory. Not just from religious fanatics, but the common folk too.
The sex itself, is merely adding to how light hearted the entire affair is, that people get so caught up in festivities that public sex is not noteworthy. A ritual execution is as light hearted as a music festival.
Now, the lore implications of the entirety of the festivities are:
- This is not an isolated or special case.
It isn't the first execution of its kind. People know and expect them and will prepare around them.
- These executions are seen as a good thing.
It is not just some holy order persuing justice, but some sort of task that even commoners believe in. With it not being hidden away from the common folk either, they're straight up aware of it and are delighted by it.
- Whomever the order is that is enacting these executions, appears to have control over the region.
There doesn't appear to be any dissent showing signs that their authority is being challenged. They are seemingly freely able to capture and execute individuals, meaning they are in power and are backed by the public opinion.