First up I'll say I do think there's scope for a studio here that makes more of a feature of BDSM themes in combination with anal sex. For myself I'll say I'm not desperately interested in the bondage aspect or typical clothing but would like to see more of a focus on spanking/flogging, nipple clamps/manual play, and (100% safe) breath play (fucking while hand over mouth/nose or round neck). All very much shot with a willing submissive, nothing forced. This is actually why I'm less keen on the bondage aspect. I'm not into what I'd consider more extreme BDSM, with needles etc.
As for the title question, I guess the answer is often to present an emotionally darker theme, and be reminiscent of a dungeon/basement? Do you have any particular scenes in mind here which you'd have like more if they'd been brighter lit? Porn World (formerly DDF) 'BDSM' scenes tend to be brighter lit but are generally tamer than what most may have in mind by true BDSM. A couple of particularly brightly lit examples:
Scene:
https://pornbox.com/application/watch-page/35928
Scene:
https://pornbox.com/application/watch-page/45861
What do you think of the lighting in the NRX BDSM scenes? It's only a little darker than their normal scenes I'd say, and not like it's hard to see the models as a result. Personally I like it. For example:
Scene:
https://pornbox.com/application/watch-page/115266