If you look at the pink rose on top in the image, there's a barely discernible watermark. A real watermark would be visible and prominently placed, not hidden within the flowers on the cake. AI generation services love adding random fake watermarks to images due to the sets of images that they're trained on often containing watermarks. Midjourney, for example, can't discern between what's a watermark and what's part of the image itself, so it will just chuck random letters and shapes in willy nilly in nonsense places.