its 4-2-1 but the way they made it its really just 4-2 where the rest of the exhaust counts as the 1. look at the picture closely and you will see a piece of metal dividing the top and bottom outlet of the header which makes it a 4-2-1. there just isnt enough room in the celica to make a length of pipe that has two pipes.
Upon inspecting the images closer... Yes, I think you are right in this regard, still seems a bit odd, the transition from the 2-1 seems a bit short to make any noticable difference. Definitely better than the stock unit, tho.
Can't wait to see dynos!