The supporting leg will often do a plié (bend) as a preparation and lift its heel off the ground. (And if you are raising the heel the plié really helps - as does engaging your core)
And I suspect that is where Raqia got it from. Love her dance style - but she has a different understanding of "truth" and "facts" than I have.Back in October 2003 I attended at workshop with Raqia Hassan at Fantasia in London. I think it was one of the first ones she did in the UK and I diligently made notes. She was demonstrating the arabesque step and said that it originated with the Ghawazi (as a very low, flat-footed step, much as she demonstrates in the video Dunyah posted) and that it had been adopted into ballet - hence the term "arab"esque and the lifted leg became much more lifted and into the ballet line. I believe she demonstrated it with the lifted leg being kept very low for the Ghawazi style and a little more lifted for oriental (if memory serves me well).
I've no reason to doubt Raqia, and certainly I've seen footage of the Banat Mazin sisters doing a similar step. However, I've never heard this explanation anywhere else.
And I suspect that is where Raqia got it from. Love her dance style - but she has a different understanding of "truth" and "facts" than I have.
The ballet term has nothing to do with arabesque curved lines in the pose, it is named after the figures in arabesque art. Apart from curving and twining lines and intricate patterns, "arabesque" art had more to do with classical Greek/Roman art than anything Arabic.