You can now edit your images on the fly using the new editor available on every image Metafield.
To see the new feature, login to your Cosmic JS account and go to any Object with an image Metafield and you'll notice a button to edit "Settings". (Note: you will need to have a role that includes developer features)
Click the button and you will be able to edit and optimize the image using imgix query params.
If you have any questions about this feature or others, join the conversation on Slack and reach out to us on Twitter.