The image size from an automated build is different from the image created on a mac using virutalbox and boot2docker.
Example: docker hub repo: wtsidney/lastpass-cli the boot2docker tag is 22MB larger.
I did not expect to see any differences.
$ uname -a
Darwin Williams-MacBook-Pro.local 15.5.0 Darwin Kernel Version 15.5.0: Tue Apr 19 18:36:36 PDT 2016; root:xnu-3248.50.21~8/RELEASE_X86_64 x86_64
$ docker -v
Docker version 1.11.1, build 5604cbe