I don't get it either. Maybe it's one of those interpretations of PJ that we'll never really understand--he interpreted that because there is the Argonath, there must also be statues of Elves everywhere in Lorien and Rivendell.
Now that I googled it, Gilraen's statue looks a lot like the Virgin Mary's in Catholic churches.
Couldn't find other statues too, but I remember they look a bit like that too. Like old Catholic statues.