At first I tried to imagine what could explain the reduced height of the oval in periods 5, 7-9. I thought this was a kind of sign.

When the moon is close to the horizon it looks very big, I reasoned. Consequently it must look smaller when high in the sky. From the calendar in Mamari I have the impression that during the month the moon flies higher and higher in the sky and then, after the time of full moon, he (as the moon often has a canoe-shape) slowly descends again.

The reduced size when not near the horizon could be explained as due to the moon being close to us when near the horizon and far away when near the phase of full moon. In the same way as Mars sometimes is faint because he has traveled far away.

And then we can reach a similar explanation for the high small glyphs in the middle of the Keiti-week: In the middle of the day the sun ought to be high and far away like the moon, and as the week too is the domain of the sun the middle of the week must be high and far away.

It all makes a kind of sense. But we need no explanation. There is no mark in the form of reduced size. The size is normal and not reduced.

However, now that we have the explanation it may be turned upside down (mirrored) to explain why glyphs are big in the beginning and the end.