Well that’s very interesting. I’m guessing this is a proprietary scent that got added to the standard by whoever from the industry.
If I was designing it, it would definitely be fire-y. It would be a bad smell if I was being realistic, full of lizard bile sort of smells mixed in with partial combustion products, but nobody wants to be immersed in that. So, I guess the question is what sort of fire is dragon’s breath?
It’s supposed to be pretty hot, so maybe it’s a metal sort of fire, but then again you don’t really see that in the natural world. Acetylene and friends could do the same, although I’m not sure what that smells like exactly. Maybe I would split the difference between organic and metallic and go with a burning beeswax/hot metal combo, which shouldn’t be too gross.