This wood sculpture is a homage inspired by Heihachi Hashimoto, 'About the Stone', 1928, Wood.
https://www.meer.com/henry-moore-institute/artworks/61703

The artist left the following words.
"In this work, I have painstakingly copied the form of the stone onto the wood. The artistic value of sculpture is not, of course, to imitate nature, but to be something completely different, yet possessing qualities that guarantee the reality of the natural world, that is, to be a stone, but with a life that transcends and is free of stone. Such a stone exists within the stone. A stone that transcends being a stone." (Omitted below.)

Ida focused on the face, which he often uses as a motif, and expressed it in wood.
This is not a head sculpture, but a face expressed in wood. So the back side is a precipice.