This is not a ezdataflow feature but should be an eZ Platform feature in [the roadmap](https://discuss.ezplatform.com/). I post it here not to forget. As an ezdataflow user, i would like to see the difference between two versions after an flow update in eZ Platform backoffice : <img width="1105" alt="image" src="https://user-images.githubusercontent.com/409996/69741227-fbe3b100-113a-11ea-8b62-13e24c97f728.png">