A campaign for Playboy Argentina puts paparazzi in public showers and restrooms. Comparate to this campaign from Kellogg's that also transformed stall walls into something else.
Copy on the towel below reads, "I can be a March playmate" (source: Coloribus).
This is a from a different Playboy outdoor campaign, where they placed mirrors to get the upskirt metaphor going (source: Iconema).
And, of course, you remember this classic Playboy billboard in Germany.