It really is a lovely photograph, but I'm not seeing any blatantly obvious upside-downs in it.. I'm going to have to have a look at this and try and work it out :)
I don't get the challenge aspect. (The only thing that looks like it might be upside down is one of the pictures right in the middle but under all the others. The only other thing I can think is the "Asia's on the other side of the world from me" take -- but that's very subjective to my geographical point of view.) It's an interesting montage of photos that looks great. Depending on the look you're going for, it seems a little too yellow to be sepia-toned -- I might try backing off on that a bit.
I am having a difficult time determinig the 'upside down' aspect of this photograph. None of the pictures in the photo appear to be uspide down and the camera doesn't appear to be upside down either. I'm not sure if I am missing somethin here or not. I will look at it again after the challenge to see if you have commented on your intentions with this photo...