The label showcased here is affiliated with one of the finest Super Powers prototypes of all time, The Tower of Darkness. I hesitate to call this a proof since it exhibits full production qualities. The label, similar in thickness to a movie poster, would be affixed to the cardboard box itself once those were printed. It measures a whopping 27 inches in height and 24 inches in width. If you look at a large vehicle like the Darkseid Destroyer, you'll notice it consists of a cardboard box with a paper portion adhered to it. The Tower of Darkness box construction was planned in this exact manner. Unfortunately, no examples of the cardboard portion have surfaced.
The shot above shows a closeup of the top left corner of the label. It features a nice shot of the Tower of Darkness playset. It is difficult to tell from the picture, but the playset shown here has blue darkseid hands. In contrast the playset shown on the 3rd series cardback features purple hands. For those of you keeping track, we can guarantee at least two prototype playsets were produced for photography.
Next we see the label's top right corner. Featured are two spectacular shots showing off the playset's various action feature including moveable capture hands and evil hero torture wheel. This playset was indisputably packed with great play value!
Finally we have the bottom left corner closeup. The smaller photo on the label shows a nice rear view of the Tower of Darkness. Parademon is standing on a moveable platform. When this platform moved downwards it caused the plastic chain holding Wonder Woman to raise up. Yet another example of the fine features planned for Darkseid's evil lair.
I've documented only two surviving examples of this box label in collectors' hands to date. Their existence yields two hypotheses in terms of how far along packaging was at the time of cancellation. First, it is possible that packaging was fully ready for the toy. Secondly, the two labels possibly served as a catalog photography sample and packaging mockup for industry shows like Toy Fair. I currently subscribe to the latter theory. Regardless, it is amazing that two package labels survived for what I consider the most sought after Super Powers prototype of all time.