Levi has a unique glyph version of this symbolism included as a frontispiece for "The Magical Ritual of the Sanctum Regnum":

It’s also interesting to note how this seems to be a reflection of the lady’s shape in The World (or Universe) card. (Mostly in the Golden Dawn influenced decks.)

The shape is also the G∴D∴ 3°=8° Altar symbol
Note that the B.O.T.A. deck is the only one that depicts the Tau identifiably as such. Although, Waite did use a latin “T” as the hanging post. In Crowley’s deck, the symbol hanging from the Tau is replaced with the Golden Dawn’s 0°=0° Altar symbol: