They are already layered together. To cut each layer out they have to be separated then ungrouped. If you select one of the images you'll see that there is no Hide Contour button, only an Edit Group button.

This is what an image looks like using an Imagine:



Using any other Cricut:



Hide Contour isn't available on these images.

This is what it looks like once the layers have been separated (notice that there's still no Hide Contour button:



None of the individual pieces can be copied or manipulated in any way until they are Ungrouped.

Once that's done each piece can be manipulated. (But there is still no Hide Contour button - at least on this image anyway.)



I'd say the reason that Hide Contour isn't available is that these images were created mainly to be printed and cut on the Imagine (although they can be cut on the other Cricuts). Hiding Contours would make the image print incorrectly.

The single Layered Images from Create a Critter that were added recently work in the same way.