I'm late to this thread, but this needs to be said for any less experienced climbers looking in this thread:
DO NOT SET UP YOUR RAP USING A TAG LINE IN THIS WAY; YOU COULD END UP DEAD
Always make sure that you set up the rap in such a way that you could load only the larger (dynamic) rope safely; that is, ensure that even if your tag line was not getting enough friction and so was slipping through your belay device, that you have a biner or some other device will prevent the entire setup from slipping through the anchor. In this example, the rap ring and knot are on the WRONG side of the v-thread.
In this pic with the v thread, is the tag line running through the v thread holes? Have not seen that setup before, although also haven't climbed with a tag line either, so wondering if that is a typical setup. Obviously leaves nothing behind when you pull the ropes, but I'd be concerned (not having tried it before) with friction when trying to pull them.