Generally the source code to your Rails app is shared from your own filesystem to the virtual machine you're running with Vagrant; it is not stored on the virtual machine's drive. The application is never actually stored permanently on the box. Thus, sending it to someone else will not allow them to run the app, as the app doesn't exist on the VM.
For more info, see "Accessing the Project Files" on the Vagrant SSH Documentation:
Accessing the Project Files
Vagrant bridges your application with the virtual environment by using a VirtualBox shared folder. The shared folder location on the virtual machine defaults to /vagrant
, but can be changed. This can be verified by listing the files within that folder in the SSH session:
vagrant@vagrantbase:~$ ls /vagrant
index.html Vagrantfile
The VM has both read and write access to the shared folder.
Remember: Any changes are mirrored across both systems.