1)The inks are really dark, which means there is a TON of ink on that image, making it next to impossible to remove it from the backing.
2)The sheet type you have is especially difficult to remove if you don't do it regularly because of the "tattered" edges.
After quite a few customers calling me with these type EI disasters, I started removing the images for the customers before they even left the store. Depending on the image, I will put it on parchment paper to keep it from re-sticking, or just lay it back on the original backing. I haven't had a customer call with a problem since.
The responses earlier about using the edge of the counter and the fridge to make it remove are both spot on. The fridge works better with heavier inks, i've found, than does the counter edge. However, be very careful not to leave it in the fridge too long (more than 15 minutes at the absolute longest) or it will crack.
Finally, next time you order an image, ask if they use a new style paper that doesn't have the tattered edges, prints to the edge, and removes by just a simple peel, no matter how much ink is on it. We use this paper now for all of our images and it is a dream.
But really, I think your transfornmer turned out just right without the image. I recognized it as bumblebee before I even began reading what went wrong.