Two sturdy legs (stilts of a ladder) hold him steady as he chisels, so the opening stays safe.
With every tap of his craft tool (工), the hollow (穴) grows-until the 空 above pours in: endless pale blue and drifting clouds.
A paper lantern from Obon slips through the gap-festivals send wishes into the sky; imagine kitsunebi (fox-fire) flickering beside it, a little ghostly glow.
Wind whistles like a distant flute and taiko echoes, teaching you: hole + tool = 空 (sora/kū) - a constructed emptiness that becomes a sky.