As a lab owner, you can now enable specialized images from the shared image gallery (SIG) attached to your lab for lab users to create machines from.
There are two operating system states supported by Shared Image Gallery today, generalized and specialized. Generalizing as the name states is a process that removes machine and user specific information from the VM. Images that are required to retain machine and account specific information are known specialized images. For specialized images, SIG users can create image versions without the need for generalization using sysprep (Windows) or deprovision (Linux) from any of the possible sources (VMs, snapshots, managed images).