Votive tiles (J. senbutsu) are relief images of Buddhist deities created in large quantities using molds. They are said to have been hung in rows as decoration for the interior walls of pagodas and Buddhist halls to achieve a space resembling a cave temple replete with a Thousand Buddhas motif. These have images of a seated Buddha appearing within the hexagonal frame of each tile. In spite of their small scale, what remains of these tiles from the latter half of the seventh century convey the vivid spirit of Hakuho-era art. 
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Produced in mass quantities in a mold, senbutsu are votive tiles with images of Buddhist deities in relief. These are thought to have been arrayed across the inner walls of Buddhist buildings, creating spaces of splendorous adornment (Skt. vyūha and alaṃkāra; J. shōgon). The stretched hexagonal shape of these votive tiles with seated Buddhas is unusual. Though small in scale, their vivid expression is truly captivating.
 
NAKAGAWA AyaEnglish by Mary Lewine 
Buddhist Art Paradise: Jewels of the Nara National Museum. Nara National Museum, 2021.7, p.351, no.14. 

These three fragments belong to two thick tiles which had probably elongated hexagonal shape. The image of Nyorai (Tathāgata), seated on a lotus seat, is represented in high relief on each of the tiles. These images do not have ornaments on their heads. Their round faces look as innocent as children, and some aspects which are common to Buddhist statues of the Hakuhō period are observable. The shoulders and arms of the figure are covered by sleeves, and wave-shaped drapes cover the breast. The hands which are folded on the lap are covered with a cloth, which implies a kebutsu Buddhist image. The kōhai-halos surrounding the figures' heads are flaming. The lotus seat consists of three layers of plain petals. The holes of nails are visible above the shoulders of the images near the rim of the tiles, which indicates that the tiles once could have been nailed to walls. These hexagonal tiles are very important because there is no other extant example of this kind.
Excavation projects were carried out at the ancient site of Tengei-ji temple twice in the past, in 1979 and 1989 and it has been confirmed that tiles were buried underground at the site. 
Masterpieces of Nara National Museum. Nara National Museum, 1993, p.128, no.101.