This Bonus Episode begins with a recap of all what happened just before Prue's death.
The we see a demon attacking Phoebe (Just like the source wanted). Then we see Piper and Prue in the manor and no one's there to help them. Prue's spirit starts floating and disappears when phoebe finally comes to the manor with the reversal spell, but it was too late. She calls for Leo and he orbs in and tries to heal the sisters but only Piper woke up. Leo keeps trying to heal Prue but he realized that she was already dead and there was nothing he could do.
Now, this is just a simple video of what happened after Shax closed the door. I only did it just to fill the void in some of the fans who still wonder what really happened. So please don't consider this as a fan-made episode. I only showed what was a bit like the real thing. The rest is up to your imagination.