Quote further explained (appreciated).

[ole32]

“The bonds that held his body were loosened. He felt very cold, he was shaking uncontrollably, his teeth were chattering, the tears were rolling down his cheeks. For a moment, he clung to O’Brien like a baby, curiously comforted by the heavy arm around his shoulders. He had the feeling that O’Brien was his protector, that the pain was coming from outside, from some other source, and that it was O’Brien who would save him from it.”

How can this passage be so important moreover, a focus?

Is this passage really symbolic of some moment?

I understand that Winston felt O'Brien was the only one who could save him, at the time. An example of manipulation on the party's part.OF HOW DEEP THEY CAN PENTRATE INTO YOUR MIND

[The Atheist]

I don't think it's anything terribly symbolic. Stockholm Syndrome, maybe?

It's simple human nature to want to have someone on whose shoulders we can cry. It's maybe part of W's re-education and beginning to accept doublethink, but beyond that, I doubt any major significance.