Directly nothing but considering that Festool also has a rail, substitute the Festool rail and it could be nice for those who prefer Festool. Also, I understand that the same company who made the rail in the photo plans to make a rail that will fit the Hilti. Both the Hilti and the Festool saws have standard european measurements. Therefore the "made for Hilti rail could work with the Festool saw.
Also from previous conversations with the owner of this forum, he has a great interest in being able to do quality miters with his Festool saw - He just might like to borrow the idea or maybe check out the commerical version when it is available.
Have a good evening.
Burt