Much like creating Announcements on a page, the UC Image Rotator requires a Contact Sheet to be created first; the component itself is simply a lens that references this. In the CQ GUI, create a page in your site with the "Contact Sheet: Image Rotator" template. Be sure to hide this page from navigation.
When building a contact sheet for UC Image Rotator, there are several required fields. Click and drag the UC Image Rotator Item component from the sidekick, then click "Edit."