/usr/lib/x86_64-linux-gnu/libgdk_pixbuf_xlib-2.0.so is in libgdk-pixbuf2.0-dev 2.36.5-2+deb9u2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libgdk_pixbuf_xlib-2.0.so.0.3600.5