Look closely at that screenshot.
The statue is clearly in the image of Nald'thal, as depicted in the Arrzanaeth Ossuary and Milvaneth Sacrarium.
Above his head, at the peak of the arch is the mark of Azeyma, a sun-disk within a bowl.
A few things are going through my head at the fact that these are being depicted together. Before I go into a full blown speculative and incohesive blabber, what are others thinking?
Edit: While I'm at it...
This is the entrance of the Sunken Temple of Qarn, found a little south at Broken Water and is clearly a temple to Azeyma. It carries identical architecture to what is found exposed at Highbridge.
Still mulling this over...