That’s interesting, my labels and inbox, outbox etc are all underneath those

Interesting, I’ve seen that on desktop and mobile app for nearly a decade.

Gmail sorts email by tab. Click the triple lines and you’ll see Primary, Promotions, and Social. Basically Gmail didn’t like the word spam, so they named the folder promotions.

I think it’s talking about emails in the Promotions tab with the word “ad” in a box at the beginning of the subject line.