The actual rules don't say that I think, it's more about the intention that the watermark is embedded with the image/multimedia itself, so it's persisting even if someone "right-click > save" the image or takes a screenshot, not literally regulated the watermark has to be unremovable.
> (Summary) The icon should be directly embedded into the deep fake or published text (except for creative works), unless equivalent alternatives are available such as a user interface overlay. The icon must be visible when content is reshared or downloaded.
> It says the icons are optional. So that icon must not be what the other person was talking about.
What "watermark" are they talking about if not the label/icons? The label/icon in question are what the whole "EU Icons for labelling AI-generated content" thing is about, someone correct me if I'm having a big brain fart.
That sounds like one possible implementation, not the goal per se. The goal (the explicit/stated one at least) is to give people a heads up what's AI generated vs not, when that's unclear.
> (Summary) The icon should be directly embedded into the deep fake or published text (except for creative works), unless equivalent alternatives are available such as a user interface overlay. The icon must be visible when content is reshared or downloaded.