The PictureField Viewer tool is almost identical to the Picture Viewer. The difference is that it displays pictures already stored in ACT! whereas the other tool displays pictures stored outside of ACT!. Pictures are stacked on top of one another and you can scroll through them using VCR-like buttons. Pictures are automatically adjusted to the size of the control. It offers a number of different options like rotating, naming, etc.
Clicking a picture displays it in a popup window.
See this video on how to set it up.