Originally Posted by ColorChange

I can only speak for myself. I need a longer TT than normal geometries. You can get this in three ways, longer TT, seat back, longer stem or bars with more reach. If I size up with a larger frame to get the longer top tube, the bike feels too large and I have a hard time getting enough bar drop. If instead, I size down, the frame is lighter and stiffer, handling is quicker, I get better drop, but I have to slide the seat back and/or lengthen the stem.

Here is what mine looks like from an older shot.


Obviously the OP's set up really looks extreme (and probably wrong IMO), but in general, longer torso's can result in setback seat and or longer stem.