Based on what users on platforms like X and Reddit have shared, it appears that Gemini 2.0 Flash does have some trouble removing certain types of watermarks, such as semi-transparent watermarks.

Gemini does add its own subtle watermark to the final image: a small blue diamond in the bottom left hand corner. In addition, the AI model sometimes struggles to completely remove transparent and ...

The model also isn’t a perfect watermark remover. Gemini 2.0 Flash appears to struggle with certain semi-transparent watermarks and watermarks that canvas large portions of images. Still ...