In order to get better answers, you should tell us whatever you can about where in the book you think the answer is. I am assuming you are talking about the part in Chapter 33 where Pip and Estella happen to be driving by Newgate Prison. Pip has just been there the day before.
When she asks Pip what that place is, he pretends at first not to know. In my opinion, this shows that he still places Estella on a pedestal. He thinks that she is too good and too delicate to even have to think about such things as prisons.
You can see this attitude of his in this quote from the end of Chapter 32:
I thought of the beautiful young Estella, proud and refined, coming towards me, and I thought with absolute abhorrence of the contrast between the jail and her.