Every generated image now comes out in the aspect ratio you configure. Until today, the selected ratio was silently dropped on the way to the image model, so all output — across OpenAI, Google, and BytePlus models, for both in-app and plugin generations — was rendered in the model's landscape default no matter what you chose.
The configured ratio now travels all the way through to the image model. If you ask for a 4:5 portrait, you receive a portrait; if you ask for 16:9, you receive that. Nothing changes for generations that were already using the default landscape ratio, and no action is required on your side — simply select the aspect ratio you want and it will be applied to the result.