According to other Wikipedia articles (https://sv.wikipedia.org/wiki/Sorex_lyelli https://sv.wikipedia.org/wiki/Sorex_lyelli), almost half of that length is the

According to other Wikipedia articles (https://sv.wikipedia.org/wiki/Sorex_lyelli https://sv.wikipedia.org/wiki/Sorex_lyelli), almost half of that length is the tail, so that might explain it. Also, I assume most of the "bulk" you see in the photos is fur (which a small mammal in a harsh climate needs a lot of for insulation).