So I was asked a little while ago for some more details on the workings of the box joint jig I made quickly a while ago and posted on here. I was going to write up a detailed explanation with some photos, however a quick google search saved me the job! The animation I found on the linked website explains how my jig works exactly... with far more clarity than I could have achieved with some writing and a photo! I hope this solves any confusion, comment if not!
Thanks for the interest!