Metoro mostly explained this type of glyph with hetu'u (star).

However, sometimes he said ahi (fire) or Raá (Sun).

1. This glyph type shows the sun. Although raá means 'sun', 'day', 'time', it does not necessarily mean that GD12 glyphs cover all these meanings. And there may be other meanings, though presumably not completely different ones. Stars (hetu'u) were sometimes called 'little suns'.

"In the Maori tongue the word ra denotes the sun, as it does, with some dialectic changes, throughout Polynesia, and as it did in Babylonia and Egypt. Komaru and mamaru also denote the sun, but are seldom heard. These three names are also applied to a canoe-sail, though one fails to see any connection between the two." (Best)

2. There are similarities between the sun and the fires made by humans. Both are giving light and warmth. When Metoro sometimes said ahi (at GD12 glyphs) it is therefore understandable.

"In reference to your question, 'How do the natives of Easter Island obtain fire?' I [Mr. Croft] have to answer that they cannot tell. Their forefathers, like the ancient Romans, had their 'vestal' fires, preserved from ancient times; but the 'Vestal Virgins' of Easter Island were gray-headed and gray-bearded old heathen priests. It was a part of their duty, sacredly attended to, to guard the eternal fire, which was neutral, together with its guardians, in all wars.

From this sacred fire the whole community - at one time a large one - could obtain that useful 'element' from time to time, as they needed it, for culinary and other purposes. This custom is still kept up by a portion of the community, while another portion rely on the matches of Mr. Dutrou-Bornier for their supply.

Another portion of the community have learned from Gambier Islanders (who were sent there by the Catholics, to assist the priests) how to make fire: not by rubbing two sticks together, as you ask in your letter, but by rubbing the point of one stick on the side of the other, until it makes a hot groove and eventually fire - a work generally of from five to ten minutes. In order to illustrate this, I have had a photograph taken for you, showing you the natives in the very act of producing fire, and have also sent you the identical sticks used on that occasion.

You will notice that the wood is of a soft and spongy nature. It grows abundantly on these islands, and is a variety known as the Hibiscus tiliaceus, and called by the natives 'Purau' and 'Fau', pronounced 'Purow' and 'Fow', 'ow' being sounded as in the word 'how'. You can, if you wish, obtain large quantities of it, by going on board the vessels carrying oranges from these islands to San Francisco; the orange crates are mostly made of it. And you could also get one of the Tahitian or other islanders, sailors on board of such vessels, to make fire for you by the aid of these sticks, and thus practically or ocularly answer your own question, as they are all experienced in the art." (Churchill)