/usr/lib/x86_64-linux-gnu/libcsfml-window.so.2 is in libcsfml-window2 2.1-2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libcsfml-window.so.2.1
/usr/lib/x86_64-linux-gnu/libcsfml-window.so.2.1