Confused as to what is actually being done here

This journal is what QuickFile creates if you have “post net wages to balance sheet only” turned OFF in your settings. I wrote an explanation of this in a reply on another thread a few days ago that may help clear things up

Essentially the journal is moving the money twice, from A to B and then from B to C. The fact that B (net wages) is listed in both columns is what makes the debit and credit totals look doubled, but the net effect is still just £120 moving from A to C.