Never mind, it works on Explorer, just not on Firefox for me - I wasn't getting anything showing up between the words "Before" and "After". It's just blank (even when I quote or look at the edit screen)
Really weird that, as the other three images show up on Firefox (and you'd think between the two, Explorer wouldn't be the one that works better... which is why I stopped using it).

It's hard to tell on the photos - is it obvious that it is different in person?