Okay much easier to see now.
You can see the entire complex is rotation CCW. So as the lower jaw swings forward and up, the upper jaw the upper jaw is rotating along an invisible fulcrum. Basically the back of the upper jaw comes down, and the front moves sightly up (this might move forward, too depending on the bone and how the teeth are placed).
In general, I'd say prepare for a larger lower jaw, shorter face, and with regard to your question about the philtrum area, I'd guess that area gets more "sunken" in. That isn't a guarantee to happen, but as the upper jaw rotates you could theoretically lose some support there. This is why Dr. Gunson grafts the area. Almost everyone I have spoken with says those grafts don't do much. But then again, we can't see those patients without the grafts to compare. In poor lighting that shows depth of lines in the face you might notice a worsening in the smile line region, IMO. The lip support should improve.
Overall, it should be an improvement over the current situation, but likely will have a few issues mentioned above that you have to weigh. There are also the increased risks of revision to consider.