They're designed to reestablish your aetherisl essence safely. Given their entire purpose is around detecting and manipulating aether, they don't need much explanation beyond 'put this in the lowest concentration of any aether within a certain range'

Shadow fingers established very well how aetherial travel functions and why we can bring shit with us (also explaining in the process, iirc, how weapons end up locked to one player), and you can extrapolate from there