When adding new media of type Image you can upload your image file, add metadata like title and alt text and then submit the new media. After the upload of the image a thumbnail is shown, but because the file entity created is temporary no image styles are created. This shows a broken image to the user.
Also generate image styles for temporary images as the image itself is also already uploaded to the blob storage and deleting the temporary image will clean up the image styles.
Active
2.3
Code