If the image was stored in the container using the Insert Picture ... command, the container should show the image in it already. You can either have that container show a thumbnail size image or scale the large image (with the associated speed penalty).
To display the full (larger) size image you could...
1) make the container field into a button and attach it to a script that...
2) opens a new window / layout that shows the larger image (which may be a different container with the larger image)
Thanks, I've been able to get it working.