In the 'calendar' of the day in Large Santiago Tablet (H) we find tagata (GD15) at noon:

It is reasonable to symbolize the highest point of the sun with a standing person. Earlier - during a.m. - the sun has been growing (by way of the eating gesture). The last phase of the development is seen in Ha6-1.

At noon, though, he must be fully grown, because during p.m. he will shrink.

Ha6-3 is a glyph which indicates 'center', a straight vertical line inside a cartouche-like oval perimeter. That information is not conveyed by the standing man.

In Ha6-4 the 5 marks at right tell about a place where the canoe of the sun changes direction, i.e. it stands still (although just for a short moment of course) exactly as at summer solstice. The straight vertical line at left indicates 'stop' (for the a.m. 'season').