Suggestion:

This type of glyph, I am convinced, stands for The King.

(Though whether this glyph, Ga6-3, represents a real king on Easter Island, 'ariki mau, or a mythical celestial king is not clear to me at the present moment.)

Ideas:

1. Kingship is shown by arms and legs like the shape of X.

2. On his head there seems to be some type of head-gear. But that is not neccessary to indicate kingship. Presumably it indicates some ceremonial function.

3. In this specific glyph the legs are 'open', but not the 'arms'. This certainly is a sign indicating something. Multiple other signs are also present, e.g. the length, broadness etc of each of the four members and the exact apperance of the headgear.