I think that that is exactly what it does.Shannon SteelSlave wrote:... It can't be that the restraints slide up or down the slots.
...
If you take a closer look at the last photo, especially at the victims left hand (her left, not ours) you can find two details:
a) There is a pair of parallel vertical slots in the table over her hand and
b) The outline of the strap tied around her wrist is tearshaped with the tip pointing into the inner slot.
I believe that there is some sort of slide guided by the outer vertical slots. These are probably connected with a horizontal bar, that can be pulled up by turning the wheel at the head of the table.
Provided that the straps are also connected to either the sliding pieces or the bar itself you end up with a completed rack.
Attaching the straps to the slides/sleighs would pretty much ensure that the loops don't get tighter without pulling the wrists up, too.