akkonrad

$ docker history imagename
IMAGE               CREATED             CREATED BY                SIZE
f770fc671f11        12 seconds ago      apt-get install -y curl   21.3 MB
28445c70c2b3        39 seconds ago      apt-get install ping      11.57 MB
8dbd9e392a96        7 months ago                                  131.5 MB

$ docker tag 2844 imagename   # <-- that's the secret right there

$ docker history imagename
IMAGE               CREATED             CREATED BY             SIZE