Amazon Web Services : ECR supports Docker Image Manifest V2, Schema 2

Previously, you could only use a single tag per image limiting the amount of contextual information like 'environment' or 'version' that could be associated with an image in ECR. Now, you can assign multiple tags to an image allowing you to capture additional information for control, audit, and security purposes. The List and DescribeImages APIs have been updated to return all the associated tags for each image in your repository and you can see the full set of tags for an image in the ECR console. You can also now use the AWS APIs to add and remove tags (via PutImage and BatchDeleteImage) making it easier to track images as they progress through dev and test environments by changing tags remotely rather than pulling the image locally, tagging, and re-pushing to ECR via Docker Engine.