Yeah, I think those stems are different lengths.

I've drawn some lines that should represent the axial center of the stem and the crossing points inside each clamp. My lines are obviously not centered with the near faces, but I think they're pretty close to the middle plane of the stem given the camera perspective.

If you want to look at this photographically, take the image from a lot further away, without zoom. This will eliminate much of the perspective. If your camera is high enough resolution, then the detail will be fine w/out zoom. Do you think you can find somebody with a sweet camera?

You can just tape-measure these on your screen to see that there's a big difference in the two lines.