"... Post a full body pic of your completed Halo related (Master Chief, ODST, Cortana, etc) costume(s)..."
The picture of the Marine costume is not complete. The person posting says they have a helmet, but it's necessary to show it, in a full body picture (as per the original instructions) for the costume to be considered complete.
* Further, the picture is a rear view of someone in BDU's with a bit of a back-pack, a butt plate and maybe some shoulder pieces. I think we need to see a bit more to call this costume complete.