On my rucksack, the straps at the top of the shoulder straps help tighten my rucksack to the shape of my body. Access to my water bladder holder is inside my rucksack. If the photo is showing how to access a water bladder from the outside that looks a good idea to me but the only one thing I would query about it is, if it's on the outside of your rucksack would your body heat warm up all of your drinking water? My internal one warms a small amount of my water, I'm not keen on drinking warm water, but it only lasts for the second and third mouthful, (I just spit them away) then it's cool water again.