The left arm is the set-in version (the sleeve on the right above) and the right arm is the version the way the jacket was designed (the sleeve on the left above - very confusing, I know). To me, the original one looks like you were trying to set in a sleeve but didn't quite make it. I even pressed the seam allowance towards the jacket (as indicated in the pattern), but still wasn't happy with the look.
The back of the sleeve seems to pull odd on the non-set in style too. Please ignore the overlay near the armhole above - it's not sewn down yet so it puckers a bit there.
I'm going with the set-in sleeve side. It's only moved in about 1/2 inch, but seems to make a huge difference in my opinion.
Up next - the lining.
Until next time - Happy Sewing!