why are my VirtualBox Ubuntu images different from the same DO distros?

I was fooling around with configuration management tool Ansible, recently, and was surprised to discover that my local development VirtualBox instances of Ubuntu Lucid had different components than DO Ubuntu Lucid instances. In my case, this led my configuration to succeed locally, but fail on DO, which kind of undermines a basic premise of development on local VMs.

So, what might account for the differences users will find between local development distros (as managed by Vagrant) and those same versions on DO?

PS - Perhaps it’s relevant to note that I’ve been experimenting with the smallest DO Ubuntu images – is this a basis for the problem I describe?

Thanks, G