Right, and doesn't the only other seam go right through your pocket? Seems to me he's marked the right one for a small adjustment.
Doesn't look like it needs to be any smaller to me, but I'll defer to the tailors. I'd also suggest you always "model" with a shirt, tie and proper trousers, to get a better idea how it's fitting. Unless you normally wear it with your car-repair attire. ;)