To my eyeballs, it looks like the trigger stop is still present in the slot. It takes zooming in to see it.
To the OP: Loosening the screw allows one to place the stop where you may want it. Then secure it by tightening the screw.
IMNHO, this wasn't a great trigger stop implementation. As already noted, it some cases it was advisable to remove it altogether. A screw loctited in the trigger, or S&W's other method - a rod inside the rebound spring are far better.
