Those same features can be seen on the other stone-pulling photos, convincing me that all the photos are of the same stone. I think all the photos come from a two volume 1917 publication entitled Nias: Ethnographische, geographische en historische aanteekeningen en studien, by E. E. W. Gs. Schroeder. From what I gather, one of the volumes is text while the other is photographs. I don't have access to either at the moment (let me know if you have it?), but I'm guessing all the Nias stone-pulling photos in the previous post come from the volume of photographs.
A panoramic view of Bawömataluo (D) shows the chief's house in relation to the stone that is used for the Hombo Batu (stone jumping) ritual (down the street to the left). In Hombo Batu, young males jump over the stone (which is over 2 m high) in order to prove that they are adults (and/or worthy of being warriors). This is still done today and is apparently a tourist attraction, as it is easy to find numerous photos online. This video has some nice, high quality footage of the village and shows a man jumping over the stone. This video offers an explanation of the tradition and some background on competitive feasting and conflict on Nias.
This whole scenario may be explained completely (perhaps with additional photos) in Schroeder's ethnography or in some other source. I hope I can have a look at it some day.
According to this desciption submitted to UNESCO by The Ministry of Culture and Tourism of the Republic of Indonesia, the horizonal stones represent males and the vertical stones represent females. Saonigeho (or Siliwu Gere) was the individual who finalized the construction of the chief's house.