I think Crowley's re-naming of the Strength card is another New Aeon nuance. The old meanings of Strength are still present in the new design, but there is an added twist that is amplified by the new name, Lust.
In the old card there is a woman closing the jaws of a lion. She is controling and redirecting the raw animal potency, symbolised by the lion, and sublimating and transforming that force into another form. (Hence the lemniscate above her head.) In essence it's a symbol of the willed redirection of sexual energy for the purposes of spiritual development. But in the old Aeon conception of the card it is a one way journey. The lower manifestation of this energy was thought to be fallen, and must therefore be raised up to a higher more spiritual level. (Sex energy and "spirit" are different manifestations of one force.)
It was Crowley's belief that the New Aeon heralded the full activation of the Path of Teth for humanity. This required a bit of a re-design of the card, and the name of the card needed to be tinkered with to express this new understanding. As we all know Crowley chose the word, Lust. His reasoning was that the word Lust implied Strength, but also the joy of Strength exercised. The old meaning of the card is still present, but now there is an added dimension. Lust & power of Lust (exercised).
Choose ye well!
26. I am the secret Serpent coiled about to spring: in my coiling there is joy. If I lift up my head, I and my Nuit are one. If I droop down mine head, and shoot forth venom, then is rapture of the earth, and I and the earth are one.
I think it is interesting that Atu XVI is mentioned in the next verse because it is intimately linked with Atu XI. If Atu XI is the causal force, then Atu XVI is the place where that force manifests.