/var/lib/lemonldap-ng/portal/skins/impact is in liblemonldap-ng-portal-perl 1.9.16-2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/lemonldap-ng/portal-skins/impact
/usr/share/lemonldap-ng/portal-skins/impact