A few preliminary remarks and imaginations:

1. This type of glyph possibly illustrates the concept of 'the living water of Tane' (vai ora a Tane). There may be water in the middle oval and there are four flames like the reflexes from water. The number four may indicate the four 'corners' of our 'earth', which is the receiving part.

The sun was associated with water among other ancient peoples too, e.g. among the early Babylonians and among the Maya indians:

"But beyond their role as points of communication with the Underworld, James Brady of George Washington University has told us that in the Maya mind caves were intimately associated with mountains, and that it is in such caves that it was and still is believed that fertilizing rain is created before being sent into the sky; even today ceremonies are held inside them at the onset of the rainy season." (The Maya)