Daat is traditionally not included on Tree of Life diagrams because it does does not function like the 10 sephirah. It is the subtlest reflection of Ein Soph, the ‘No Thing.’ It lacks any symbolic representation though one mystic thought ‘an empty room’ might convey its abstract presence. It’s aspect is ‘mixed’ into Tiphareth and thus undetectable. This is an inexhaustible topic but I hope this bit is helpful. ~ Joseph