Okay, so since you used a 'Style', it would essentially add additional text/prompt to your input prompt to 'steer' the image to the selected style.
Here is how the prompt is set up using the 'Fantasy Portrait' style on the t2i-framework-plugin
generators like ai-text-to-image-generator:
, d&d, fantasy, highly detailed, digital painting, artstation, sharp focus, fantasy art, character art, illustration, 8k, art by artgerm and greg rutkowski. It's an absolute world-class masterpiece artwork. It's an aesthetically pleasing artwork with impeccable attention to detail and impressive composition.
So, with the prompt adding 'greg rutkowski' (and artstation) it would add some kind of signature (or watermark) with it. You can view what the styles are adding on this styles import page.