This type of glyph (GD16), presumably 'vai ora a Tane', is found also in Sunday in the text of P.

Although Tane and Tu do not appear in the Easter Island pantheon (Buck) there surely must have been a concept uniting sun and the heavenly water. They were Polynesians and sweet water was scarce on Rapa Nui.

I believe that GD16 was useful for the writer when he wished to express 'the sun' or its corresponding god, whoever that might have been.