@ Everyone, thanks for your comments.
Most of them were quite enlightening. Trying to make sense out of this epi.- in the 1st chapter of my OS The Realisation, I have written about Sati & Devi Shakti seeing each other, where Devi Shakti makes Sati realiise her true self. This epi looked simillar, Sati coming to meet Parvati, to convince her, not to give away the Damaru. Regarding Sati & Parvati being same, they are aadi Shakti's form. When Durgama can appear in Nava-Durga forms at a same time, why can't Parvati's inner conscious take Sati's form to stop her making the mistake?