The SHA-256 checksum of the downloaded file
https://www.torproject.org/dist/torbrowser/6.0/TorBrowser-6.0-osx64_en-US.dmg
is on my computer
0f4f6ca01028c2956c811dd94d67a76feb507cad176c031f32e6f95873003b4c

But according to the text file
https://dist.torproject.org/torbrowser/6.0/sha256sums-unsigned-build.txt
the SHA-256 checksum of the file
TorBrowser-6.0-osx64_en-US.dmg
should be
d68d01889ba38764ebf2057b3cd3263f638a74205031a6d1df11ab8ca13a3618

Why the mismatch?