Priyanka is clearly doing drama of being Pro-Archana😆 She remembers the nomination backstabbing but she wants public to see what a great friend she is. She also knows Archana can flip on her anytime, she is prepared. Once Archana attacks, Pri will walk away with all the sympathy, backstabbed by friend whom she went out on a limb to support. At the sametime she has extra vote against chugli gang as long as Archana stays loyal. Right way to deal with Archana👍🏼
She also deliberately did that Main balidaani hoon drama to garner sympathy. It was calculated, as she got rattled by the outside feedback by Sallu which she did not like. She tried to turn it around by using the only point that could go in her favour - sacrifice 
BB was bang on about Pri in one thing, "Chit bhi meri aur pat bhi meri".
I can't fault her for doing this because the whole house is basically against her and setting a narrative constantly. She only has herself to vocally inform people what she is. So the constant I am this, I am that, she keeps doing. She has to set her narrative against theirs constantly.
She is playing really well. Her only undoing is overdoing the I, Me, Myself and possibly believing she really is some selfless martyr. Serial ke character ko kuch zyaada hi seriously maan lete hai real life mein bhi aise hi hai, Sumbul is also in imlie mode constantly 😆