Where do you see that on this photo?

The white label with the "Haltungsform" is a standard label used in the German meat industry, showing under what conditions animal was kept before being slaughtered. 1 is the worst, and 5 is the best: https://haltungsform.de/en/

In this one, it says "Käfighaltung" under 2. Which means "caged keeping". So I assumed it's a kinky reference to a chastity cage. Maybe too much of a jump I know but I'm not a native German speaker and all the times I heard about a cage in German, it was in a kinky context.

Now that you asked and I looked at the source, apparently it's part of a working environment themed sticker set: https://www.threads.com/@unterwegselektrisch/post/DD34uR6uJG...

It's embarrassingly wrong but very funny too :)