If you look closely, you will see that the rifle is fitted with an altered rod bayonet barrel and the front sight is pinned at the front.
The rifle's receiver was manufactured in 1907, well after the .30-'06 cartridge was adopted. The rifle, therefore, was never fitted with a 1905 rear sight.
The rifle was assembled in 1908 using mostly leftover parts drawn from Ordnance Stores at Springfield Armory. One must remember that Springfield Armory accumulated in Ordnance Stores very large quantities of unassembled parts, including loose barrels and receivers, during 1905 and again during 1906-07. And those parts had to eventually get assembled into complete rifles.
J.B.