The link count tells us how many files share images in commons. We expect 2: one in commons and one in a site. 3 or more means multiple sites share the image.
Note: we denote long hash codes as ...jpg which should be duplicated as found.
cd .wiki ls -l commons
We see one link count of 3.
-rw-r--r-- 3 root root 264777 Mar 13 21:27 ...jpg
We find all three copies of the same file.
find . -samefile commons/...jpg
All three are found.
./scad.fed.wiki/assets/plugins/image/...jpg ./commons/...jpg ./photos.ward.dojo.fed.wiki/assets/plugins/image/...jpg