The poporo glyph type indicates a time of darkness, and at the same time says a 'seed of light' has been 'planted', which gives hope of a coming lighter season.

 

The 'seed' is the 'head' of the previous light season. The vertical straight 'stem' is the same sign as in the center of henua ora, though inverted, which means it is the opposite: a station of 'birth':

 

The ika glyph type with a poporo sign (kahi) carries both meanings, both a 'rising fish' and 'birth'. If kahi is inverted it means both a 'sinking fish' and a station of 'death', as for instance in the preview of the year in K: