Web Page: Enter the hyperlink for image button to navigate too, enter the description to define the alternate text for the image.
Button Group: Select groups image will be associated with. To add additional groups for selection modify Column within List.
Button Order: Number used to arrange images in a group lowest to highest.
Image Vertical Alignment: Configure the cell vertical positioning; useful when images vary in height.
Image Horizontal Alignment: Configure the cell horizontal positioning; useful when images vary in width.
Rollover Image: (Optional) Url source of additional image displayed on Mouseover event.
Rollover Group: (Optional) When using single row will specify Button Group to display on Mouseover event.
NOTE: Always use relative URL address for both Web Page and Rollover Image when content is within Site Collection.