The Watermark Is Pointless
That extremely (to say the least) annoying diamond watermark is pointless because there are workarounds. This includes cropping it out.
When it can't be cropped out without cropping essential portions of the image, the workaround is to ask for a revision (such as "extend the area of grass below her feet), which forces the watermark lower down on the image, where it can then be cropped out without cutting off key parts of the image. Another workaround is to attach the image in chat and ask chat to "remove the diamond in the lower right and fill naturally."
In summary, there's no point in this watermark being programmed in; anyone with mediocre tech abilities will figure out how to omit it. This can be a pain, but it CAN be done, and gets done all the time. I've used a ton of Gemini generations so far -- and none show a watermark.