the seat in the foreground is for the driver, the seat next to the breech is the gunner, the seat folded up further back is for the commander. the boxes on the floor were for ammo, and the t-34 had no turret basket so as the turret rotated, the loader had to walk around on those, which might be empty and open from hurried loading. his seat is the triangle folded up on the left
next to the commander's seat looks to be ready racks for more ammo. the 2 recoil buffers are below the breech of the main gun and the (elevation? traverse?) handle is in front of the gunner. the green box mat be a heater core or something. the center thing under the gun is probably a rotating connector to supply power to the turret