Yeah, it would seem the library extends the client with libbitcoin explorer and Bitcoin explorer, which are command line apps.
Well bitcoind is a command line app, but it's still an app and still a client, as it's an executable. If libbitcoin is truly a library, it will be just a bunch of class & header files, with no executables. But I've never used libbitcoin to actually check whether or not it includes an executable.