Shutterstock would say that the model is a derivative work of their images, much like a photograph of a painting is a derivative work of the painting despite being in a different medium.
They would say they are owed licensing fees regardless of whether the shutterstock logo appears in the output. The appearance of their logo in the output merely proves that the system's outputs are derived from their copyrighted images.
They would say they are owed licensing fees regardless of whether the shutterstock logo appears in the output. The appearance of their logo in the output merely proves that the system's outputs are derived from their copyrighted images.