Out of curiosity I looked at my listing online and found that Airbnb has so-called discounted it so it's saying that instead of £808 for 21-26 Aug it's now available for £709.
Now I don't change my prices, it's the same all the time so where has this come from?
The discount is less than 15% (99/808 = about 12%), so it's not the Top-rated guest discount. In my screenshot above you'll see it shows up to me as a custom promotion (60 day median discount) with strikethrough.