In Winclone 6, we changed from Block-based imaging to File-based imaging based on the standard Windows WIM format. You can read the specifics on the differences in the Block-based imaging versus WIM based imaging support article. In File-based imaging, you do not need to shrink the filesystem prior to cloning, since Winclone does a File-based clone that only clones the used files on the Windows Volume.
You can restore the prior behavior of Block-based imaging by setting the "Use Block-Based Cloning" preference in the Winclone Preferences. Once you enable that setting, any images that create will be block based images, and you will see the Shrink and Expand options in the Tools menu.