The hau tea glyph type is a stylized picture of the horizon in the east with a sun 'eye' (at right in the glyph) together with the horizon in the west (at left in the glyph), connected by (in the north) the 'roof of the sky' with vertex at noon:

Sky 'roof', sun 'eye', and the two horizons where sun will rise and go down, are connected, and in between is a rectangular area in which Easter Island lies.

In the middle of the glyph a third vertical line is drawn as a theoretical construct (not real, not connected with the rest of the glyph).

It is the imagined line between Vinapu and Anakena, a line reaching from the south pole to the north pole, a line for 'generating fire'. It is a line to induce a new 'sun' (year) in midwinter after the old one has 'gone out' (cfr the glyph type vae and also how the Polynesians used a 'fire plow' for creating new fire).

The meaning of hau tea is basically 'day light', the kind of light which during summer magically makes everything grow.