more questions and ramblings about the US cover art

I've had a few more minutes to think about (and look at) the cover art, specifically the US cover. Here are some random thoughts:

• It's probably not a dementor, it's probably Voldemort. I checked the US chapter art with the dementor, the face wasn't shown at all. And the face on the DH cover, with red eyes and a snakelike appearance (what you can see of it) fits the description of Voldemort. So, is this the final battle between him and Harry?
• They're wearing identical, and rather tattered, robes. Brown ones. Not black. What's up with that?
• They don't have wands.
• There are curtains hanging on the sides. That gave me the impression it's an arena, almost like the one where the veil is located except this one appears to be outside. That looks like a sky, albeit a strange colored one. So I thought the black blobs in the background were heads. They reminded me of the heads looking up at the Dark Mark on the cover of HBP. Then I looked again and I thought the blobs were headstones. Like in a graveyard. Then I looked again and thought they really look more like heads. Well, so look like heads, some look like headstones. But it's likely that they're all the same thing (or are they?). Who knows.