It's shorter than a USRA tender. Perhaps you are refering to the tall coal bunker?
If you are, it's that high as that is typical of Canadian practice. The tender's been kitbashed so that the coal space is narrower so the crew can walk past the coal bunker, which has been made higher to off-set the narrower coal space.
The loco now looks much different than in those photos as it's lost the Russian domes and had a few other minor changes made to it.
It now looks like GER No. 163 see: -
Roger T. Home of the Great Eastern Railway at:- http://www.highspeedplus.com/~rogertra / Latitude: 48° 25' North Longitude: 123° 21' West