A
Alan.P
Maybe i'm reading it wrong!?! The way i see it, if you're cutting trim around a window, it would need to be layed in the mitre block. If you lay it against a wall ie. if you were only tiling to half room height, you'd stand it up in the mitre block.
I don't see the difference in where you lay it to, it depends onto which wall your going to lay the back of the trim / flange to, that determines what technique. Whether it stops half way up and stops at a 3 way mitre or a horizontal trims underside.