From www.bleepingcomputer.com: OpenAI is testing a new watermark for its Image Generation model within the ChatGPT 4o framework, primarily aimed at users who create artwork resembling that of Studio Ghibli.

This watermark will be applied to images generated by free users, while subscribers of ChatGPT Plus will be able to save images without the watermark.

OpenAI is also developing an ImageGen API to allow developers to create their own applications using this advanced model.