Indeed seems to be the case. [1] I expect it's widely ignored however unless the Swiss use the internet differently from the citizens of just about every other country on earth.
[1] https://www.ifolor.ch/en/inspire/image-rights-in-switzerland
[1] https://www.ifolor.ch/en/inspire/image-rights-in-switzerland
Being in the background of someone else's holiday photo isn't a problem, but you can't just post publicly identifying photos of people where they are the subject of the photo if you do not have consent.