The more I look at this, the less it concerns me. I don't know why you can't get a clear pic, but that's not really an issue. Here are some of my M&P 45:
As you can see, there are no such "tabs" on my frame. However, I'm not convinced it's an issue. They could simply be left over plastic from the mold process.
Here's a mark I found on my frame:
This little "scallop" is on the left side in the same area as yours. It may have been made as a worker removed extra plastic. It may have been made as I've used the gun. I don't really know because I've never looked closely at this part of the frame before.
However, it's a non-issue. The slide doesn't ride on this part of the gun. In fact, it only touches the frame at these four points indicated by the red arrows:
Previously I said to call S&W. I'm going to amend that now. If you call them, they will tell you to send it in. When they get it, They will cut the plastic "tabs" off and ship the gun back to you. You will not have the gun for a month and they won't really make any real repairs to the gun that you can't do yourself.
So, take your time and examine the gun closely. As you re-install the slide, see if it contacts those raised tabs. If it doesn't, or just barely touches them, cut them off and get on with your life. If the slide is rubbing on them hard, then you have an issue that must be addressed by S&W.
Anyway, that's how I feel about it after putting in some thought. Let me know if you have any questions about what I said.
