Make sure you do the comparison of the two pictures at 1:1. These
differences are tiny and probably caused by a different preview size for
the two files. When you do a compare in Lightroom, the sharpness of the
"fit" image is strongly influenced by the size of the preview built for the
specific file which is determined by lots of factors (have you ever zoomed
in on the image, etc.). Lightroom shows you a downscaled image generated
from those previews in Fit view. The difference between these two images is
probably due to this. You should also see that as soon as you have zoomed
in to 1:1 and then zoom back out, the previews should look very similar
suddenly as Lightroom now has full size previews generated on both files.
It's also good advice to set the standard preview size (catalog settings)
to a number that is higher than your screen resolution. Nowadays this means
that you should usually select the highest number available.
P.S. sharpening at 150 is really extreme. You should never have to go that
far except maybe for out-of-focus images to try to rescue them. Usually
when people get to values that high, they are trying to sharpen the Fit
view in Develop. This often leads to very distorted sharpening and noise
reduction amounts as the preview in Develop for sharpening and noise
reduction is not at all correct for extreme values when zoomed out. So it
is very important to only touch the sharpening and noise reduction sliders
at 1:1 or higher zoom. They are meant to increase pixel-level sharpness,
not sharpness after downscaling which is dealt with by output sharpening if
you downscale in Export.
