The reason why it had "Contortion" in the title was that Sally originally thought she only did contortion, plus a little bit more. The compression was the major part of it, as it not only linked contortion and elasticity, but it was what caused the two to become interested in each other.
I think I have read that story once or twice in the past, and I may have gotten the spark for the idea of this one, but that one was primarily about contortion rather than linking contortion to elasticity.