Image by Toban Black
These ads are in a lot of phone booths in the UK.
If I’m not mistaken, these ads generally sell sex workers (who most people would describe as "prostitutes".) (I also noticed ads that offered massages; but given the other stickers they’re pasted up with, I have doubts about whether those ads truly are just about massages.)
The ads in this phone booth are just text — without images, which seemed a lot more common. There is a lot of nudity on other versions of those ads.
Some people refer to the ads as "call cards."
(I haven’t read most of those articles, myself.)
Here’s a blog post about those sex ads –
"Phone Box Advertising Norms" (March, 2007)